NCERT Solutions for Class 12 Maths Chapter 7 – Integrals Ex 7.10
Page No 340:
Question 1:
Answer:
When x = 0, t = 1 and when x = 1, t = 2
Question 2:
Answer:
Also, let
Question 3:
Answer:
Also, let x = tanθ ⇒ dx = sec2θ dθ
When x = 0, θ = 0 and when x = 1,
Takingθas first function and sec2θ as second function and integrating by parts, we obtain
Question 4:
Answer:
Let x + 2 = t2 ⇒ dx = 2tdt
When x = 0, and when x = 2, t = 2
Question 5:
Answer:
Let cos x = t ⇒ −sinx dx = dt
When x = 0, t = 1 and when
Question 6:
Answer:
Let ⇒ dx = dt
Question 7:
Answer:
Let x + 1 = t ⇒ dx = dt
When x = −1, t = 0 and when x = 1, t = 2
Question 8:
Answer:
Let 2x = t ⇒ 2dx = dt
When x = 1, t = 2 and when x = 2, t = 4
Question 9:
The value of the integral is
A. 6
B. 0
C. 3
D. 4
Answer:
Let cotθ = t ⇒ −cosec2θ dθ= dt
Hence, the correct answer is A.
Question 10:
If
A. cos x + x sin x
B. x sin x
C. x cos x
D. sin x + x cos x
Answer:
Integrating by parts, we obtain
Hence, the correct answer is B.