NCERT Solutions
Class 12 - Mathematics Part-2 - Chapter 7: INTEGRALS
Exercise 7.4

Question. 1

Integrate: \(\dfrac{3x^2}{x^6+1}\)

Answer:

\(\tan^{-1}(x^3)+C\)

Question. 2

Integrate: \(\dfrac{1}{\sqrt{1+4x^2}}\)

Answer:

\(\dfrac{1}{2}\log\left|2x+\sqrt{1+4x^2}\right|+C\)

Question. 3

Integrate: \(\dfrac{1}{\sqrt{(2-x)^2+1}}\)

Answer:

\(\log\left|\dfrac{1}{2-x+\sqrt{x^2-4x+5}}\right|+C\)

Question. 4

Integrate: \(\dfrac{1}{\sqrt{9-25x^2}}\)

Answer:

\(\dfrac{1}{5}\sin^{-1}\left(\dfrac{5x}{3}\right)+C\)

Question. 5

Integrate: \(\dfrac{3x}{1+2x^4}\)

Answer:

\(\dfrac{3}{2\sqrt{2}}\tan^{-1}(\sqrt{2}\,x^2)+C\)

Question. 6

Integrate: \(\dfrac{x^2}{1-x^6}\)

Answer:

\(\dfrac{1}{6}\log\left|\dfrac{1+x^3}{1-x^3}\right|+C\)

Question. 7

Integrate: \(\dfrac{x-1}{\sqrt{x^2-1}}\)

Answer:

\(\sqrt{x^2-1}-\log\left|x+\sqrt{x^2-1}\right|+C\)

Question. 8

Integrate: \(\dfrac{x^2}{\sqrt{x^6+a^6}}\)

Answer:

\(\dfrac{1}{3}\log\left|x^3+\sqrt{x^6+a^6}\right|+C\)

Question. 9

Integrate: \(\dfrac{\sec^2 x}{\sqrt{\tan^2 x+4}}\)

Answer:

\(\log\left|\tan x+\sqrt{\tan^2 x+4}\right|+C\)

Question. 10

Integrate: \(\dfrac{1}{\sqrt{x^2+2x+2}}\)

Answer:

\(\log\left|x+1+\sqrt{x^2+2x+2}\right|+C\)

Question. 11

Integrate: \(\dfrac{1}{9x^2+6x+5}\)

Answer:

\(\dfrac{1}{6}\tan^{-1}\left(\dfrac{3x+1}{2}\right)+C\)

Question. 12

Integrate: \(\dfrac{1}{\sqrt{7-6x-x^2}}\)

Answer:

\(\sin^{-1}\left(\dfrac{x+3}{4}\right)+C\)

Question. 13

Integrate: \(\dfrac{1}{\sqrt{(x-1)(x-2)}}\)

Answer:

\(\log\left|x-\dfrac{3}{2}+\sqrt{x^2-3x+2}\right|+C\)

Question. 14

Integrate: \(\dfrac{1}{\sqrt{8+3x-x^2}}\)

Answer:

\(\sin^{-1}\left(\dfrac{2x-3}{\sqrt{41}}\right)+C\)

Question. 15

Integrate: \(\dfrac{1}{\sqrt{(x-a)(x-b)}}\)

Answer:

\(\log\left|x-\dfrac{a+b}{2}+\sqrt{(x-a)(x-b)}\right|+C\)

Question. 16

Integrate: \(\dfrac{4x+1}{\sqrt{2x^2+x-3}}\)

Answer:

\(2\sqrt{2x^2+x-3}+C\)

Question. 17

Integrate: \(\dfrac{x+2}{\sqrt{x^2-1}}\)

Answer:

\(\sqrt{x^2-1}+2\log\left|x+\sqrt{x^2-1}\right|+C\)

Question. 18

Integrate: \(\dfrac{5x-2}{1+2x+3x^2}\)

Answer:

\(\dfrac{5}{6}\log\left|3x^2+2x+1\right|-\dfrac{11}{3\sqrt{2}}\tan^{-1}\left(\dfrac{3x+1}{\sqrt{2}}\right)+C\)

Question. 19

Integrate: \(\dfrac{6x+7}{\sqrt{(x-5)(x-4)}}\)

Answer:

\(6\sqrt{x^2-9x+20}+34\log\left|x-\dfrac{9}{2}+\sqrt{x^2-9x+20}\right|+C\)

Question. 20

Integrate: \(\dfrac{x+2}{\sqrt{4x-x^2}}\)

Answer:

\(-\sqrt{4x-x^2}+4\sin^{-1}\left(\dfrac{x-2}{2}\right)+C\)

Question. 21

Integrate: \(\dfrac{x+2}{\sqrt{x^2+2x+3}}\)

Answer:

\(\sqrt{x^2+2x+3}+\log\left|x+1+\sqrt{x^2+2x+3}\right|+C\)

Question. 22

Integrate: \(\dfrac{x+3}{x^2-2x-5}\)

Answer:

\(\dfrac{1}{2}\log\left|x^2-2x-5\right|+\dfrac{2}{\sqrt{6}}\log\left|\dfrac{x-1-\sqrt{6}}{x-1+\sqrt{6}}\right|+C\)

Question. 23

Integrate: \(\dfrac{5x+3}{\sqrt{x^2+4x+10}}\)

Answer:

\(5\sqrt{x^2+4x+10}-7\log\left|x+2+\sqrt{x^2+4x+10}\right|+C\)

NCERT Solutions Class 12 – Mathematics Part-2 – Chapter 7: INTEGRALS – Exercise 7.4 | Detailed Answers