Definite Integration Question 486

Question: The area between the curve $ y={{\sin }^{2}}x, $ $ x- $ axis and the ordinates $ x=0 $ and $ x=\frac{\pi }{2} $ is

[RPET 1996]

Options:

A) $ \frac{\pi }{2} $

B) $ \frac{\pi }{4} $

C) $ \frac{\pi }{8} $

D) $ \pi $

Show Answer

Answer:

Correct Answer: B

Solution:

Required area $ A=\int_0^{\pi /2}{{{\sin }^{2}}x.dx}=\int_0^{\pi /2}{( \frac{1-\cos 2x}{2} )}dxa $

$ =\frac{1}{2}[x]_0^{\pi /2}-\frac{1}{4}[\sin 2x]_0^{\pi /2}=\frac{\pi }{4} $ .