Definite Integration Question 25

Question: $ \int_0^{\pi }{{{\sin }^{2}}xdx} $ is equal to

[MP PET 1999]

Options:

A) $ \pi $

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

C) 0

D) None of these

Show Answer

Answer:

Correct Answer: B

Solution:

$ I=\int_0^{\pi }{{{\sin }^{2}}xdx=2\int_0^{\pi /2}{{{\sin }^{2}}xdx}} $ ,

$ \because \int_0^{2a}{f(x)=2\int_0^{a}{f(a-x)dx}} $ , if $ f(2a-x)=f(x) $

$ I=2\times \frac{1}{2}\times \frac{\pi }{2}=\frac{\pi }{2} $ .