Change log: page 5

New topics, content updates, published corrections, syllabus checks and new versions of the privacy policy and terms, newest first. Typo fixes are not listed: they do not change what a page teaches.

2092 changes Latest 7 Nov 2026

Page 5 of 11 · 200 changes on this page

November 2026

  • Integrated rate equations

    Correction Chemistry Chemical Kinetics

    Scope integrated laws and pressure equations; clarify disappearance constants, saturation limits and pseudo-first-order interpretation.

  • Temperature dependence of rate

    Correction Chemistry Chemical Kinetics

    Correct Arrhenius/Maxwell interpretation, transition-state language and catalyst thermodynamics; scope temperature and parameter assumptions.

  • Collision theory

    Correction Chemistry Chemical Kinetics

    Separate collision counts, molar rates and rate coefficients; clarify energy-factor, threshold and orientation-model limits.

  • Group 13 elements

    Correction Chemistry The p-Block Elements

    OpenAI Codex read the full published lesson, FAQs and practice; corrected factual errors and overclaims, distinguished traditional exam models from modern bonding, checked sources and recomputed answers. New unpublished draft; simulations unchanged.

  • Group 14 elements

    Correction Chemistry The p-Block Elements

    OpenAI Codex read the full published lesson, FAQs and practice; corrected factual errors and overclaims, distinguished traditional exam models from modern bonding, checked sources and recomputed answers. New unpublished draft; simulations unchanged.

  • Group 15 elements

    Correction Chemistry The p-Block Elements

    OpenAI Codex read the full published lesson, FAQs and practice; corrected factual errors and overclaims, distinguished traditional exam models from modern bonding, checked sources and recomputed answers. New unpublished draft; simulations unchanged.

  • Group 16 elements

    Correction Chemistry The p-Block Elements

    OpenAI Codex read the full published lesson, FAQs and practice; corrected factual errors and overclaims, distinguished traditional exam models from modern bonding, checked sources and recomputed answers. New unpublished draft; simulations unchanged.

  • Group 17 elements

    Correction Chemistry The p-Block Elements

    OpenAI Codex read the full published lesson, FAQs and practice; corrected factual errors and overclaims, distinguished traditional exam models from modern bonding, checked sources and recomputed answers. New unpublished draft; simulations unchanged.

  • Group 18 elements

    Correction Chemistry The p-Block Elements

    OpenAI Codex read the full published lesson, FAQs and practice; corrected factual errors and overclaims, distinguished traditional exam models from modern bonding, checked sources and recomputed answers. New unpublished draft; simulations unchanged.

  • Position in the periodic table

    Correction Chemistry The d- and f-Block Elements

    OpenAI Codex reviewed the full published lesson, FAQs and practice, corrected factual errors and overclaims, verified primary sources and recomputed answers. New unpublished draft; simulations unchanged.

  • Electronic configurations

    Correction Chemistry The d- and f-Block Elements

    OpenAI Codex reviewed the full published lesson, FAQs and practice, corrected factual errors and overclaims, verified primary sources and recomputed answers. New unpublished draft; simulations unchanged.

  • Occurrence

    Correction Chemistry The d- and f-Block Elements

    OpenAI Codex reviewed the full published lesson, FAQs and practice, corrected factual errors and overclaims, verified primary sources and recomputed answers. New unpublished draft; simulations unchanged.

  • General properties

    Correction Chemistry The d- and f-Block Elements

    OpenAI Codex reviewed the full published lesson, FAQs and practice, corrected factual errors and overclaims, verified primary sources and recomputed answers. New unpublished draft; simulations unchanged.

  • Important compounds

    Correction Chemistry The d- and f-Block Elements

    OpenAI Codex reviewed the full published lesson, FAQs and practice, corrected factual errors and overclaims, verified primary sources and recomputed answers. New unpublished draft; simulations unchanged.

  • Experiment: KMnO₄ titrations

    Correction Chemistry The d- and f-Block Elements

    OpenAI Codex reviewed the full published lesson, FAQs and practice, corrected factual errors and overclaims, verified primary sources and recomputed answers. New unpublished draft; simulations unchanged.

  • Lanthanoids

    Correction Chemistry The d- and f-Block Elements

    OpenAI Codex reviewed the full published lesson, FAQs and practice, corrected factual errors and overclaims, verified primary sources and recomputed answers. New unpublished draft; simulations unchanged.

  • Actinoids

    Correction Chemistry The d- and f-Block Elements

    OpenAI Codex reviewed the full published lesson, FAQs and practice, corrected factual errors and overclaims, verified primary sources and recomputed answers. New unpublished draft; simulations unchanged.

  • Applications

    Correction Chemistry The d- and f-Block Elements

    OpenAI Codex reviewed the full published lesson, FAQs and practice, corrected factual errors and overclaims, verified primary sources and recomputed answers. New unpublished draft; simulations unchanged.

  • Werner’s theory

    Correction Chemistry Coordination Compounds

    OpenAI Codex read the complete published lesson, FAQs and practice; corrected factual errors and overclaims, verified sources and recomputed answers and isomer counts. New unpublished draft; simulations unchanged.

  • Experiment: double salts

    Correction Chemistry Coordination Compounds

    OpenAI Codex read the complete published lesson, FAQs and practice; corrected factual errors and overclaims, verified sources and recomputed answers and isomer counts. New unpublished draft; simulations unchanged.

  • Ligands and other terms

    Correction Chemistry Coordination Compounds

    OpenAI Codex read the complete published lesson, FAQs and practice; corrected factual errors and overclaims, verified sources and recomputed answers and isomer counts. New unpublished draft; simulations unchanged.

  • Nomenclature

    Correction Chemistry Coordination Compounds

    OpenAI Codex read the complete published lesson, FAQs and practice; corrected factual errors and overclaims, verified sources and recomputed answers and isomer counts. New unpublished draft; simulations unchanged.

  • Isomerism

    Correction Chemistry Coordination Compounds

    OpenAI Codex read the complete published lesson, FAQs and practice; corrected factual errors and overclaims, verified sources and recomputed answers and isomer counts. New unpublished draft; simulations unchanged.

  • Bonding: VBT and CFT

    Correction Chemistry Coordination Compounds

    OpenAI Codex read the complete published lesson, FAQs and practice; corrected factual errors and overclaims, verified sources and recomputed answers and isomer counts. New unpublished draft; simulations unchanged.

  • Metal carbonyls

    Correction Chemistry Coordination Compounds

    OpenAI Codex read the complete published lesson, FAQs and practice; corrected factual errors and overclaims, verified sources and recomputed answers and isomer counts. New unpublished draft; simulations unchanged.

  • Importance and applications

    Correction Chemistry Coordination Compounds

    OpenAI Codex read the complete published lesson, FAQs and practice; corrected factual errors and overclaims, verified sources and recomputed answers and isomer counts. New unpublished draft; simulations unchanged.

  • Carbonyl group: names and structure

    Correction Chemistry Aldehydes, Ketones and Carboxylic Acids

    Restricted aldehyde definition to H plus carbon/H, avoiding inclusion of formic acid and formamide.

  • Preparation of aldehydes and ketones

    Correction Chemistry Aldehydes, Ketones and Carboxylic Acids

    Corrected Gattermann–Koch usual AlCl3 WITH CuCl catalyst system; limited substrate scope.

  • Physical properties of aldehydes and ketones

    Correction Chemistry Aldehydes, Ketones and Carboxylic Acids

    Corrected ethanal state at 25 C/1 atm from NIST boiling data, including practice and summary.

  • Reactions of aldehydes and ketones

    Correction Chemistry Aldehydes, Ketones and Carboxylic Acids

    Distinguished anionic and acid-catalysed neutral-nucleophile mechanisms and non-universal slow/fast labels.

  • Experiment: tests for aldehydes and ketones

    Correction Chemistry Aldehydes, Ketones and Carboxylic Acids

    Removed contradictory aldehyde-only claims throughout explanations, table, summary and quick answer; included reducing sugars/alpha-hydroxy ketones.

  • Experiment: preparation of iodoform

    Correction Chemistry Aldehydes, Ketones and Carboxylic Acids

    Clearly labelled Remsen recipe historical rather than a modern validated protocol; retained source distinction from NCERT identification test.

  • Uses of aldehydes and ketones

    Correction Chemistry Aldehydes, Ketones and Carboxylic Acids

    Clarified formalin concentration basis, commercial stabiliser purpose and 10% formalin dilution convention; retained explicitly assumed 40wt numerical exercises.

  • Carboxyl group: names and structure

    Correction Chemistry Aldehydes, Ketones and Carboxylic Acids

    Corrected C12–C18 as a common fatty-acid range rather than a definition.

  • Preparation of carboxylic acids

    Correction Chemistry Aldehydes, Ketones and Carboxylic Acids

    Corrected carbon accounting and benzylic-H condition in side-chain oxidation, including quick answer; clarified Jones reagent.

  • Physical properties of carboxylic acids

    Correction Chemistry Aldehydes, Ketones and Carboxylic Acids

    Restricted physical-state trend to straight-chain saturated monoacids and stated temperature dependence.

  • Chemical reactions of carboxylic acids

    Correction Chemistry Aldehydes, Ketones and Carboxylic Acids

    Corrected soda-lime carboxyl-carbon fate as carbonate, contrasting Kolbe CO2; qualified coupling-product expectations.

  • Experiment: tests for the carboxyl group

    Correction Chemistry Aldehydes, Ketones and Carboxylic Acids

    Corrected phenol/litmus oversimplification across lesson and practice; all acid tests interpreted with specificity limits.

  • Uses of carboxylic acids

    Correction Chemistry Aldehydes, Ketones and Carboxylic Acids

    Corrected water as vinegar largest constituent, formic acid kitchen-staple implication and total-acid inference from pH alone.

  • Structure of amines

    Correction Chemistry Amines

    Qualified pyramidal/sp3 model, removed advice to give an incorrect measured angle, distinguished rapid nitrogen inversion from carbon-centred chirality.

  • Classification of amines

    Correction Chemistry Amines

    Expanded arylamine definition to all amine classes and aryl systems; clarified neutral amino-acid structures versus zwitterions.

  • Nomenclature of amines

    Correction Chemistry Amines

    Scoped alkanamine naming to appropriate parent structures and principal groups, corrected arylamine definition.

  • Preparation of amines

    Correction Chemistry Amines

    Corrected selective N-methylation implication, excess-ammonia purity claim, acid-reduction work-up and carbon-count wording.

  • Physical properties of amines

    Correction Chemistry Amines

    Corrected incorrect exam advice on butan-1-amine solubility; added NIOSH measured miscibility and a NIST branched-primary boiling counterexample.

  • Chemical reactions of amines

    Correction Chemistry Amines

    Corrected pyridine stronger-than-amine claim, resonance-structure counting argument and proton affinity versus Gibbs basicity.

  • Experiment: tests for the amino group

    Correction Chemistry Amines

    Added test specificity, controls, acid-mole requirement and actual aniline solubility; qualified azo colour and negative interpretation.

  • Experiment: preparation of acetanilide and p-nitroacetanilide

    Correction Chemistry Amines

    Corrected anhydride-limited theoretical yield and unsupported extra acetylation by solvent; clarified pyridine role.

  • Preparation of diazonium salts

    Correction Chemistry Amines

    Scoped aryl versus alkyl diazonium definitions, corrected exact Celsius conversion and removed a universal 283 K decomposition threshold.

  • Physical properties of diazonium salts

    Correction Chemistry Amines

    Removed easy-to-handle/dry implication for diazonium tetrafluoroborates; distinguished relative persistence from explosive hazard.

  • Chemical reactions of diazonium salts

    Correction Chemistry Amines

    Distinguished reagent-specific substitution pathways from universal simple displacement and qualified Sandmeyer yield generalisation.

  • Experiment: preparation of aniline yellow

    Correction Chemistry Amines

    Corrected acid dilution sequence, limited aniline solubility, weakly acidic medium versus weak acid, and source-only carbon tetrachloride purification.

  • Diazonium salts in the synthesis of aromatic compounds

    Correction Chemistry Amines

    Replaced impossible-product claims with selectivity/condition limits for cyanation and directing effects.

  • The empty set

    Correction Mathematics Sets

    Content-quality review: Example 3 asked for n(A) although four set cardinalities were intended; revised the prompt.

  • Finite and infinite sets

    Correction Mathematics Sets

    Content-quality review: FAQ misleadingly suggested an infinite set has no cardinal number at Class 11 level; separated NCERT notation from mathematical cardinality.

  • Subsets

    Correction Mathematics Sets

    Content-quality review: FAQ counterexample needs distinct a,b; added this hypothesis. Added a<b to the quick-answer interval convention.

  • Power set

    Correction Mathematics Sets

    Content-quality review: Non-empty proper-subset formula wrongly applied at n=0 and produced −1. Added n≥1 guard, empty-set count0, explanation and synchronized formula sheet.

  • Universal set

    Correction Mathematics Sets

    Content-quality review: Definition/summary/metadata used ambiguous contains sets language; clarified that U contains elements and has the sets as subsets.

  • Venn diagrams

    Correction Mathematics Sets

    Content-quality review: Wrong partial-overlap instruction omitted reverse containment. Added equal/proper-subset cases and distinguished simplified Euler pictures from a general Venn diagram with empty regions.

  • Cartesian product

    Correction Mathematics Relations and Functions

    Content-quality review: Explicitly limited n(A) counting notation to finite sets and retained the direct empty-product proof for infinite sets. Softened an absolute Venn-diagram claim about element types.

  • Relations

    Correction Mathematics Relations and Functions

    Content-quality review: FAQ incorrectly claimed relations in opposite directions are necessarily different. Added empty relation and A=B exceptions. Made projection formula existential quantifiers explicit.

  • Functions

    Correction Mathematics Relations and Functions

    Content-quality review: Extra Q6 incorrectly equated a function on all integers with a four-pair set. Reframed as four known values of an integer-domain function. Added finite non-empty hypothesis to counting and equal-axis scales to45° claim.

  • Angles

    Correction Mathematics Trigonometric Functions

    Content-quality review: Clarified signed rotation versus nonnegative arc length, corrected approximate equality, and answered the wheel question in radians during one second rather than only radians per second.

  • Trigonometric functions

    Correction Mathematics Trigonometric Functions

    Content-quality review: The quoted reciprocal rule could imply cot is undefined where tan is undefined. Added the common-domain restriction and cot(π/2)=0 counterexample.

  • Sum and difference formulas

    Correction Mathematics Trigonometric Functions

    Content-quality review: Replaced a geometric-angle step that only directly fits a restricted diagram with a rotation argument valid for all real angles. Explicitly retained domains after cancellation and defined A,B in the formula sheet.

  • Modulus and conjugate

    Correction Mathematics Complex Numbers and Quadratic Equations

    Content-quality review: Added missing real-variable hypotheses to extra practice Q6/Q8; their modulus-square steps require real components.

  • Argument and polar form

    Correction Mathematics Complex Numbers and Quadratic Equations

    Content-quality review: Excluded both axes from the acute reference-angle algorithm, including in quick answer. Softened an unnecessarily absolute claim about proof prerequisites.

  • Quadratic equations

    Correction Mathematics Complex Numbers and Quadratic Equations

    Content-quality review: Rational-coefficient discriminant test needed square of a rational number rather than ambiguous perfect square. Added a worked complex-coefficient equation and explicit limit of discriminant sign classification.

  • Inequalities

    Correction Mathematics Linear Inequalities

    Content-quality review: Corrected claim that mixed chains cannot be inequalities; explained that3<x>1 is two lower bounds. Distinguished genuinely two-variable examples from axis-parallel linear inequalities. Replaced unnecessary legal/medical generalizations with explicit hypothetical specification

  • Solving linear inequalities

    Correction Mathematics Linear Inequalities

    Content-quality review: Temperature prompts used ambiguous between although solutions were strict; made endpoint exclusion explicit in example5 and extraQ9.

  • Fundamental principle of counting

    Correction Mathematics Permutations and Combinations

    Content-quality review: Quick answer omitted the fixed number of second-stage choices and disjointness of added cases; aligned it with the correct full explanation.

  • Permutations

    Correction Mathematics Permutations and Combinations

    Content-quality review: Added n≥1 to factorial recurrence and circular arrangement formula. Replaced unsupported specific past-paper and categorical school-exam claims with precise scope of the extension.

  • Combinations

    Correction Mathematics Permutations and Combinations

    Content-quality review: Ball-selection questions needed individual distinguishability to justify binomial coefficients; made the assumption explicit. Added m≥3 to the collinear-point formula case.

  • Binomial theorem

    Correction Mathematics Binomial Theorem

    Content-quality review: Clarified formal n+1 term count before substitutions, fixed blanket not2terms claim at n=1, and supplied nonzero/radical domain conditions in extra practice.

  • General and middle terms

    Correction Mathematics Binomial Theorem

    Content-quality review: Greatest-term FAQ failed at x=0 (T0 and zero denominators) and called opposite-sign terms equal for negative x. Added zero-input and a=0 cases, absolute-value language and ratio-domain restrictions.

  • Sequences

    Correction Mathematics Sequences and Series

    OpenAI Codex content review: clarified domains, indexing or model assumptions; independently checked worked examples and practice. See per-topic review findings.

  • Series

    Correction Mathematics Sequences and Series

    OpenAI Codex content review: clarified domains, indexing or model assumptions; independently checked worked examples and practice. See per-topic review findings.

  • Arithmetic progression

    Correction Mathematics Sequences and Series

    OpenAI Codex content review: clarified domains, indexing or model assumptions; independently checked worked examples and practice. See per-topic review findings.

  • Geometric progression

    Correction Mathematics Sequences and Series

    OpenAI Codex content review: clarified domains, indexing or model assumptions; independently checked worked examples and practice. See per-topic review findings.

  • A.M. and G.M.

    Correction Mathematics Sequences and Series

    OpenAI Codex content review: clarified domains, indexing or model assumptions; independently checked worked examples and practice. See per-topic review findings.

  • Coordinate geometry basics

    Correction Mathematics Straight Lines

    OpenAI Codex review: corrected domain, degenerate-case and geometry explanations; independently solved examples and practice. Detailed per-topic findings retained in content-quality audit.

  • Locus

    Correction Mathematics Straight Lines

    OpenAI Codex review: corrected domain, degenerate-case and geometry explanations; independently solved examples and practice. Detailed per-topic findings retained in content-quality audit.

  • Slope of a line

    Correction Mathematics Straight Lines

    OpenAI Codex review: corrected domain, degenerate-case and geometry explanations; independently solved examples and practice. Detailed per-topic findings retained in content-quality audit.

  • Forms of the equation of a line

    Correction Mathematics Straight Lines

    OpenAI Codex review: corrected domain, degenerate-case and geometry explanations; independently solved examples and practice. Detailed per-topic findings retained in content-quality audit.

  • Distance of a point from a line

    Correction Mathematics Straight Lines

    OpenAI Codex review: corrected domain, degenerate-case and geometry explanations; independently solved examples and practice. Detailed per-topic findings retained in content-quality audit.

  • Intersection of lines and triangle centres

    Correction Mathematics Straight Lines

    OpenAI Codex review: corrected domain, degenerate-case and geometry explanations; independently solved examples and practice. Detailed per-topic findings retained in content-quality audit.

  • Sections of a cone

    Correction Mathematics Conic Sections

    OpenAI Codex content review: checked conic equations, domains, worked examples and all practice. See per-topic audit for improvements and independent calculations.

  • Circle

    Correction Mathematics Conic Sections

    OpenAI Codex content review: checked conic equations, domains, worked examples and all practice. See per-topic audit for improvements and independent calculations.

  • Parabola

    Correction Mathematics Conic Sections

    OpenAI Codex content review: checked conic equations, domains, worked examples and all practice. See per-topic audit for improvements and independent calculations.

  • Ellipse

    Correction Mathematics Conic Sections

    OpenAI Codex content review: checked conic equations, domains, worked examples and all practice. See per-topic audit for improvements and independent calculations.

  • Hyperbola

    Correction Mathematics Conic Sections

    OpenAI Codex content review: checked conic equations, domains, worked examples and all practice. See per-topic audit for improvements and independent calculations.

  • Coordinate axes and planes

    Correction Mathematics Introduction to Three Dimensional Geometry

    OpenAI Codex content review: independently checked coordinates, distances, examples and practice; clarified degenerate and signed-ratio cases where needed.

  • Coordinates of a point in space

    Correction Mathematics Introduction to Three Dimensional Geometry

    OpenAI Codex content review: independently checked coordinates, distances, examples and practice; clarified degenerate and signed-ratio cases where needed.

  • Section formula in 3D

    Correction Mathematics Introduction to Three Dimensional Geometry

    OpenAI Codex content review: independently checked coordinates, distances, examples and practice; clarified degenerate and signed-ratio cases where needed.

  • Intuitive idea of derivatives

    Correction Mathematics Limits and Derivatives

    OpenAI Codex content review: independently solved examples and practice; corrected velocity, limit cancellation and derivative-domain conditions. Simulations excluded.

  • Limits

    Correction Mathematics Limits and Derivatives

    OpenAI Codex content review: independently solved examples and practice; corrected velocity, limit cancellation and derivative-domain conditions. Simulations excluded.

  • Limits of trigonometric functions

    Correction Mathematics Limits and Derivatives

    OpenAI Codex content review: independently solved examples and practice; corrected velocity, limit cancellation and derivative-domain conditions. Simulations excluded.

  • Derivatives

    Correction Mathematics Limits and Derivatives

    OpenAI Codex content review: independently solved examples and practice; corrected velocity, limit cancellation and derivative-domain conditions. Simulations excluded.

  • Mean, median and mode

    Correction Mathematics Statistics

    OpenAI Codex content review: recalculated examples and practice; corrected grouped-data assumptions, median theorem scope, mode and dispersion edge cases. Simulations excluded.

  • Mode

    Correction Mathematics Statistics

    OpenAI Codex content review: recalculated examples and practice; corrected grouped-data assumptions, median theorem scope, mode and dispersion edge cases. Simulations excluded.

  • Measures of dispersion

    Correction Mathematics Statistics

    OpenAI Codex content review: recalculated examples and practice; corrected grouped-data assumptions, median theorem scope, mode and dispersion edge cases. Simulations excluded.

  • Range

    Correction Mathematics Statistics

    OpenAI Codex content review: recalculated examples and practice; corrected grouped-data assumptions, median theorem scope, mode and dispersion edge cases. Simulations excluded.

  • Mean deviation

    Correction Mathematics Statistics

    OpenAI Codex content review: recalculated examples and practice; corrected grouped-data assumptions, median theorem scope, mode and dispersion edge cases. Simulations excluded.

  • Variance and SD

    Correction Mathematics Statistics

    OpenAI Codex content review: recalculated examples and practice; corrected grouped-data assumptions, median theorem scope, mode and dispersion edge cases. Simulations excluded.

  • Events

    Correction Mathematics Probability

    OpenAI Codex content review: solved all event/probability examples and practice; clarified finite-space, independence, uniform-selection and replacement assumptions.

  • Axiomatic probability

    Correction Mathematics Probability

    OpenAI Codex content review: solved all event/probability examples and practice; clarified finite-space, independence, uniform-selection and replacement assumptions.

  • Types of relations

    Correction Mathematics Relations and Functions (Class 12)

    OpenAI Codex content review: checked proofs, counterexamples, domains and counts; corrected model assumptions, empty-set counting and inverse/composition scope.

  • Types of functions

    Correction Mathematics Relations and Functions (Class 12)

    OpenAI Codex content review: checked proofs, counterexamples, domains and counts; corrected model assumptions, empty-set counting and inverse/composition scope.

  • Composition and inverse

    Correction Mathematics Relations and Functions (Class 12)

    OpenAI Codex content review: checked proofs, counterexamples, domains and counts; corrected model assumptions, empty-set counting and inverse/composition scope.

  • Principal value branches

    Correction Mathematics Inverse Trigonometric Functions

    OpenAI Codex content review: checked principal branches, all examples and practice; corrected a hidden division by zero, endpoint cases and domain explanations.

  • Properties

    Correction Mathematics Inverse Trigonometric Functions

    OpenAI Codex content review: checked principal branches, all examples and practice; corrected a hidden division by zero, endpoint cases and domain explanations.

  • Matrix and order

    Correction Mathematics Matrices

    OpenAI Codex content review: read complete lesson, FAQs and practice; independently verified matrix calculations and definitions. Corrected diagonal, power and cancellation scope where required; retained verified lessons unchanged.

  • Types of matrices

    Correction Mathematics Matrices

    OpenAI Codex content review: read complete lesson, FAQs and practice; independently verified matrix calculations and definitions. Corrected diagonal, power and cancellation scope where required; retained verified lessons unchanged.

  • Operations on matrices

    Correction Mathematics Matrices

    OpenAI Codex content review: read complete lesson, FAQs and practice; independently verified matrix calculations and definitions. Corrected diagonal, power and cancellation scope where required; retained verified lessons unchanged.

  • Transpose of a matrix

    Correction Mathematics Matrices

    OpenAI Codex content review: read complete lesson, FAQs and practice; independently verified matrix calculations and definitions. Corrected diagonal, power and cancellation scope where required; retained verified lessons unchanged.

  • Symmetric and skew symmetric

    Correction Mathematics Matrices

    OpenAI Codex content review: read complete lesson, FAQs and practice; independently verified matrix calculations and definitions. Corrected diagonal, power and cancellation scope where required; retained verified lessons unchanged.

  • Invertible matrices

    Correction Mathematics Matrices

    OpenAI Codex content review: read complete lesson, FAQs and practice; independently verified matrix calculations and definitions. Corrected diagonal, power and cancellation scope where required; retained verified lessons unchanged.

  • Determinant

    Correction Mathematics Determinants

    OpenAI Codex content review: read and verified lesson, FAQs and practice. Recomputed determinants, cofactors, inverses and systems; clarified exceptional cases, signs and proof conditions.

  • Area of a triangle

    Correction Mathematics Determinants

    OpenAI Codex content review: read and verified lesson, FAQs and practice. Recomputed determinants, cofactors, inverses and systems; clarified exceptional cases, signs and proof conditions.

  • Minors and cofactors

    Correction Mathematics Determinants

    OpenAI Codex content review: read and verified lesson, FAQs and practice. Recomputed determinants, cofactors, inverses and systems; clarified exceptional cases, signs and proof conditions.

  • Adjoint and inverse

    Correction Mathematics Determinants

    OpenAI Codex content review: read and verified lesson, FAQs and practice. Recomputed determinants, cofactors, inverses and systems; clarified exceptional cases, signs and proof conditions.

  • Solving linear systems

    Correction Mathematics Determinants

    OpenAI Codex content review: read and verified lesson, FAQs and practice. Recomputed determinants, cofactors, inverses and systems; clarified exceptional cases, signs and proof conditions.

  • Continuity

    Correction Mathematics Continuity and Differentiability

    OpenAI Codex review: read full lesson, FAQs and practice; independently checked derivatives and limits. Corrected domain/endpoint and zero-denominator cases, with complete product derivatives where logarithms fail.

  • Differentiability

    Correction Mathematics Continuity and Differentiability

    OpenAI Codex review: read full lesson, FAQs and practice; independently checked derivatives and limits. Corrected domain/endpoint and zero-denominator cases, with complete product derivatives where logarithms fail.

  • Exponential and log functions

    Correction Mathematics Continuity and Differentiability

    OpenAI Codex review: read full lesson, FAQs and practice; independently checked derivatives and limits. Corrected domain/endpoint and zero-denominator cases, with complete product derivatives where logarithms fail.

  • Logarithmic differentiation

    Correction Mathematics Continuity and Differentiability

    OpenAI Codex review: read full lesson, FAQs and practice; independently checked derivatives and limits. Corrected domain/endpoint and zero-denominator cases, with complete product derivatives where logarithms fail.

  • Parametric derivatives

    Correction Mathematics Continuity and Differentiability

    OpenAI Codex review: read full lesson, FAQs and practice; independently checked derivatives and limits. Corrected domain/endpoint and zero-denominator cases, with complete product derivatives where logarithms fail.

  • Second order derivative

    Correction Mathematics Continuity and Differentiability

    OpenAI Codex review: read full lesson, FAQs and practice; independently checked derivatives and limits. Corrected domain/endpoint and zero-denominator cases, with complete product derivatives where logarithms fail.

  • Rate of change

    Correction Mathematics Application of Derivatives

    OpenAI Codex review: checked full lesson, FAQs and all examples/practice. Corrected derivative-test logic and rate/domain conditions; verified optimum values and retained sound content unchanged.

  • Maxima and minima

    Correction Mathematics Application of Derivatives

    OpenAI Codex review: checked full lesson, FAQs and all examples/practice. Corrected derivative-test logic and rate/domain conditions; verified optimum values and retained sound content unchanged.

  • Anti derivatives

    Correction Mathematics Integrals

    OpenAI Codex review: read lesson, FAQs and practice; independently checked integrals, domains and convergence. Corrected material conditions and false divergent-integral answer; preserved sound content.

  • Substitution and identities

    Correction Mathematics Integrals

    OpenAI Codex review: read lesson, FAQs and practice; independently checked integrals, domains and convergence. Corrected material conditions and false divergent-integral answer; preserved sound content.

  • Particular integrals

    Correction Mathematics Integrals

    OpenAI Codex review: read lesson, FAQs and practice; independently checked integrals, domains and convergence. Corrected material conditions and false divergent-integral answer; preserved sound content.

  • Partial fractions

    Correction Mathematics Integrals

    OpenAI Codex review: read lesson, FAQs and practice; independently checked integrals, domains and convergence. Corrected material conditions and false divergent-integral answer; preserved sound content.

  • Integration by parts

    Correction Mathematics Integrals

    OpenAI Codex review: read lesson, FAQs and practice; independently checked integrals, domains and convergence. Corrected material conditions and false divergent-integral answer; preserved sound content.

  • Definite integral

    Correction Mathematics Integrals

    OpenAI Codex review: read lesson, FAQs and practice; independently checked integrals, domains and convergence. Corrected material conditions and false divergent-integral answer; preserved sound content.

  • Fundamental theorem

    Correction Mathematics Integrals

    OpenAI Codex review: read lesson, FAQs and practice; independently checked integrals, domains and convergence. Corrected material conditions and false divergent-integral answer; preserved sound content.

  • Properties of definite integrals

    Correction Mathematics Integrals

    OpenAI Codex review: read lesson, FAQs and practice; independently checked integrals, domains and convergence. Corrected material conditions and false divergent-integral answer; preserved sound content.

  • Area under curves

    Correction Mathematics Application of Integrals

    OpenAI Codex review: read full lesson and FAQs; independently checked region boundaries, intersections and all areas. Clarified area formula domains, absolute values and ordering conditions.

  • Area between curves

    Correction Mathematics Application of Integrals

    OpenAI Codex review: read full lesson and FAQs; independently checked region boundaries, intersections and all areas. Clarified area formula domains, absolute values and ordering conditions.

  • Order and degree

    Correction Mathematics Differential Equations

    OpenAI Codex review: checked definitions, FAQs and every solution by differentiation. Added domain/branch restrictions, restored divided-out solutions, and corrected impossible-condition exam advice.

  • General and particular solutions

    Correction Mathematics Differential Equations

    OpenAI Codex review: checked definitions, FAQs and every solution by differentiation. Added domain/branch restrictions, restored divided-out solutions, and corrected impossible-condition exam advice.

  • Solving first order equations

    Correction Mathematics Differential Equations

    OpenAI Codex review: checked definitions, FAQs and every solution by differentiation. Added domain/branch restrictions, restored divided-out solutions, and corrected impossible-condition exam advice.

  • Vectors: basic concepts

    Correction Mathematics Vector Algebra

    OpenAI Codex review: read all notes, FAQs and practice; recalculated vector components, dot/cross products, sections and geometry. Clarified zero/parallel exceptions, direction signs and projection domains.

  • Types of vectors

    Correction Mathematics Vector Algebra

    OpenAI Codex review: read all notes, FAQs and practice; recalculated vector components, dot/cross products, sections and geometry. Clarified zero/parallel exceptions, direction signs and projection domains.

  • Addition of vectors

    Correction Mathematics Vector Algebra

    OpenAI Codex review: read all notes, FAQs and practice; recalculated vector components, dot/cross products, sections and geometry. Clarified zero/parallel exceptions, direction signs and projection domains.

  • Scalar multiple and components

    Correction Mathematics Vector Algebra

    OpenAI Codex review: read all notes, FAQs and practice; recalculated vector components, dot/cross products, sections and geometry. Clarified zero/parallel exceptions, direction signs and projection domains.

  • Dot and cross products

    Correction Mathematics Vector Algebra

    OpenAI Codex review: read all notes, FAQs and practice; recalculated vector components, dot/cross products, sections and geometry. Clarified zero/parallel exceptions, direction signs and projection domains.

  • Direction cosines and ratios

    Correction Mathematics Three Dimensional Geometry

    OpenAI Codex review: checked all line/direction examples, FAQs and practice; independently solved feet and distances. Corrected reversed angles and degenerate-direction conditions; retained two sound lessons unchanged.

  • Equation of a line in space

    Correction Mathematics Three Dimensional Geometry

    OpenAI Codex review: checked all line/direction examples, FAQs and practice; independently solved feet and distances. Corrected reversed angles and degenerate-direction conditions; retained two sound lessons unchanged.

  • Angle between two lines

    Correction Mathematics Three Dimensional Geometry

    OpenAI Codex review: checked all line/direction examples, FAQs and practice; independently solved feet and distances. Corrected reversed angles and degenerate-direction conditions; retained two sound lessons unchanged.

  • Linear programming problems

    Correction Mathematics Linear Programming

    OpenAI Codex review: read full lesson and FAQs; independently solved vertices, objective values, integer plans and unbounded cases. Added feasibility qualifications and missing practice constraints.

  • Conditional probability

    Correction Mathematics Probability (Class 12)

    OpenAI Codex review: read full lesson, FAQs and practice; independently recomputed probabilities and checked hypotheses. Corrected missing assumptions and misleading claims; preserved published content pending review.

  • Multiplication theorem

    Correction Mathematics Probability (Class 12)

    OpenAI Codex review: read full lesson, FAQs and practice; independently recomputed probabilities and checked hypotheses. Corrected missing assumptions and misleading claims; preserved published content pending review.

  • Independent events

    Correction Mathematics Probability (Class 12)

    OpenAI Codex review: read full lesson, FAQs and practice; independently recomputed probabilities and checked hypotheses. Corrected missing assumptions and misleading claims; preserved published content pending review.

  • Bayes’ theorem

    Correction Mathematics Probability (Class 12)

    OpenAI Codex review: read full lesson, FAQs and practice; independently recomputed probabilities and checked hypotheses. Corrected missing assumptions and misleading claims; preserved published content pending review.

  • Probability distribution

    Correction Mathematics Probability (Class 12)

    OpenAI Codex review: read full lesson, FAQs and practice; independently recomputed probabilities and checked hypotheses. Corrected missing assumptions and misleading claims; preserved published content pending review.

  • What is living?

    Correction Biology The Living World

    Clarify life-cycle features, inactive seeds and responsiveness; correct non-living size increase and dead-versus-never-living explanations.

  • Diversity in the living world

    Correction Biology The Living World

    Attribute the species estimate to NCERT and clarify accepted names, synonyms and the scope of nomenclatural codes.

  • Taxonomic categories

    Correction Biology The Living World

    Qualify the seven-rank hierarchy, developmental chordate features and comparisons of nested taxa.

  • Five kingdom classification

    Correction Biology Biological Classification

    Clarify yeast placement, group-specific exceptions and the distinction between three domains and NCERT’s six-kingdom mapping.

  • Kingdom Monera

    Correction Biology Biological Classification

    Correct bacterial multiplication versus survival and gene transfer; qualify cell walls and repair the economic-use exercise.

  • Kingdom Protista

    Correction Biology Biological Classification

    Clarify Protista exceptions, diatom-wall persistence, euglenoid heterotrophy and harmful-bloom terminology.

  • Kingdom Fungi

    Correction Biology Biological Classification

    Qualify traditional fungal groups and walls; correct plasmogamy, spore structures and refrigeration wording.

  • Kingdom Plantae

    Correction Biology Biological Classification

    Clarify plant-cell chloroplasts, nutritional exceptions and gametophyte gamete formation; improve the classification reasoning question.

  • Kingdom Animalia

    Correction Biology Biological Classification

    Correct animal reproduction and digestion generalisations, cellular organisation in sponges and plant-dependence exceptions.

  • Viruses, viroids, prions and lichens

    Correction Biology Biological Classification

    Correct CJD versus variant CJD, viral genome/replication distinctions, smallpox context and lichen pollution/taxonomy generalisations.

  • Algae

    Correction Biology Plant Kingdom

    Correct oogamy, stored-food chemistry, flagellated-cell scope and thallus terminology; qualify aquatic food-web claims.

  • Bryophytes

    Correction Biology Plant Kingdom

    Correct bryophyte transport explanation and qualify rhizoid function and typical sporophyte morphology.

  • Pteridophytes

    Correction Biology Plant Kingdom

    Qualify the typical pteridophyte body, homosporous prothallus and habitat generalisations; include rootless whisk ferns.

  • Gymnosperms

    Correction Biology Plant Kingdom

    Clarify naked seeds, pollen dispersal and Cycas female structures; attribute the cycad study precisely.

  • Angiosperms

    Correction Biology Plant Kingdom

    Clarify diplontic terminology and reproductive-resource explanation; preserve typical-trait qualifications.

  • Basis of classification

    Correction Biology Animal Kingdom

    Clarify body-cavity definitions, flatworm digestive exceptions and non-chordate neural diversity.

  • Classification of animals

    Correction Biology Animal Kingdom

    Correct animal-group generalisations and the offspring-number exercise; distinguish textbook summaries from biological exceptions.

  • The root

    Correction Biology Morphology of Flowering Plants

    Clarify root-system form versus origin and root/shoot identity independently of above/below-ground position.

  • Modifications of root

    Correction Biology Morphology of Flowering Plants

    Correct mangrove worked answer and turnip storage-organ anatomy; remove unsupported exam-choice advice.

  • The stem

    Correction Biology Morphology of Flowering Plants

    Clarify underground stems, shoot-system definition and limits of growth direction as an identification test.

  • Modifications of stem

    Correction Biology Morphology of Flowering Plants

    Correct grape-tendril position and distinguish a phylloclade from any ordinary green stem.

  • The leaf

    Correction Biology Morphology of Flowering Plants

    Correct guava phyllotaxy and unreliable leaf/leaflet orientation test; qualify identification rules.

  • Modifications of leaf

    Correction Biology Morphology of Flowering Plants

    Clarify phyllodes, pitcher development and carnivorous-plant mineral nutrition.

  • The flower

    Correction Biology Morphology of Flowering Plants

    Distinguish perigyny terminology and compound pistils; qualify literal any-plane symmetry.

  • The fruit

    Correction Biology Morphology of Flowering Plants

    Align fruit definition and quick answer with parthenocarpy, seedlessness and accessory fruit tissues.

  • Semi-technical description

    Correction Biology Morphology of Flowering Plants

    Clarify that a plus sign can separate groups within a whorl as well as distinct whorls.

  • Family Malvaceae

    Correction Biology Morphology of Flowering Plants

    Scope cotton-hibiscus characters correctly and avoid universal claims for modern Malvaceae.

  • Family Cruciferae

    Correction Biology Morphology of Flowering Plants

    Correct Brassicaceae habit, fruit and residual-endosperm generalisations; clarify turnip storage tissue.

  • Family Leguminosae

    Correction Biology Morphology of Flowering Plants

    Clarify nitrogen return and pea-type versus whole-family traits; label traditional subfamilies.

  • Family Compositae

    Correction Biology Morphology of Flowering Plants

    Clarify Asteraceae variation, fruit terminology and outdated evolutionary ranking; improve quick answer.

  • Family Gramineae

    Correction Biology Morphology of Flowering Plants

    Correct grass carpel formula, bamboo stamen generalisation and pollination assertion; qualify typical structures.

  • Plant tissues

    Correction Biology Anatomy of Flowering Plants

    Correct meristem-origin and living-tissue generalisations; clarify permanent cells, collenchyma and source–sink transport.

  • Tissue systems

    Correction Biology Anatomy of Flowering Plants

    Clarify seasonal lenticel closure, cuticle function, periderm and optional subsidiary cells.

  • Dicot and monocot anatomy

    Correction Biology Anatomy of Flowering Plants

    Clarify representative anatomy, Casparian-strip chemistry, living bulliform cells and root-thickening inference.

  • Animal tissues

    Correction Biology Structural Organisation in Animals

    Correct junction permeability, epithelial examples and muscle coordination; remove unsupported glial precision.

  • Frog

    Correction Biology Structural Organisation in Animals

    Clarify frog thrombocytes, lymphoid anatomy, partial blood mixing and species/life-stage scope.

  • What is a cell?

    Correction Biology Cell: The Unit of Life

    Clarify cell-life criteria, cellular dependence, yeast classification and zygote scope.

  • Cell theory

    Correction Biology Cell: The Unit of Life

    Clarify cell theory scope, historical wall comparison and acellular-virus exception.

  • Overview of the cell

    Correction Biology Cell: The Unit of Life

    Clarify typical cell plans, enucleate eukaryotes and wall/ribosome exceptions.

  • Prokaryotic cells

    Correction Biology Cell: The Unit of Life

    Correct pili motility, mesosome scope, wall and DNA generalisations; align practice/FAQ.

  • Eukaryotic cells

    Correction Biology Cell: The Unit of Life

    Correct membrane transport, mitochondrial ribosomes, spindle origin and chromosome scope.

  • Chemical composition

    Correction Biology Biomolecules

    Clarify shared elements, fatty-acid saturation/range, oil melting and amino-acid charge.

  • Primary and secondary metabolites

    Correction Biology Biomolecules

    Clarify primary/secondary distinction, overlapping categories and alkaloid scope.

  • Biomacromolecules

    Correction Biology Biomolecules

    Qualify size thresholds, lipid exception and cell-composition arithmetic.

How corrections are made and listed