Maths

Class 12

Maths · Class 12 · Chapter 7

Integrals

13 lessons 109 min 2 simulations

Integration runs differentiation backwards: given a rate of change, recover the function that produced it. The chapter first builds the indefinite integral, a whole family F(x) + C, and a toolkit for finding it (a table of standard results, substitution, trigonometric identities, partial fractions and integration by parts). It then turns to the definite integral, a single number that measures signed area, and links the two through the fundamental theorem of calculus and a set of properties that make many definite integrals short.

What the exam asks

JEE Main tests speed with the standard forms: spotting the right substitution, splitting a rational function into partial fractions, choosing the first function in integration by parts and recognising eˣ[f(x) + f′(x)]. Definite integrals are asked through the properties, above all the a + b − x trick, the even/odd rule and splitting at the points where a modulus changes sign. Marks are lost by forgetting + C, by not changing the limits after a substitution and by integrating straight across a point where the integrand is undefined.

Lessons

13 lessons · 109 min