Definite Integration Question 221

Question: $ \int _{-\pi /2}^{\pi /2}{{{\sin }^{2}}xdx=} $

Options:

A) $ \pi $

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

C) $ \frac{\pi }{2}-\frac{1}{2} $

D) $ \pi -1 $

Show Answer

Answer:

Correct Answer: B

Solution:

$ \int _{-\pi /2}^{\pi /2}{{{\sin }^{2}}xdx=2\int_0^{\pi /2}{{{\sin }^{2}}xdx=2\frac{\Gamma ( \frac{3}{2} ).\Gamma ( \frac{1}{2} )}{2\Gamma ( \frac{2+2}{2} )}}=\frac{\pi }{2}} $ .