Definite Integration Question 38

Question: $ \int _{-\pi /2}^{\pi /2}{\frac{\sin x}{1+{{\cos }^{2}}x}{e^{-{{\cos }^{2}}x}}dx} $ is equal to

[AMU 1999]

Options:

A) $ 2{e^{-1}} $

B) 1

C) 0

D) None of these

Show Answer

Answer:

Correct Answer: C

Solution:

$ I=\int _{-\pi /2}^{\pi /2}{\frac{\sin x}{1+{{\cos }^{2}}x}{e^{-{{\cos }^{2}}x}}dx} $

$ \because \frac{\sin x}{1+{{\cos }^{2}}x}{e^{-{{\cos }^{2}}x}} $ is an odd function,$ I=0 $ .