Definite Integration Question 123

Question: The value of $ \int _{-a}^{a}{\frac{1}{x+x^{3}}dx} $ is

[AMU 2005]

Options:

A) 0

B) $ \int_0^{a}{\frac{1}{1+x^{6}}\ }dx $

C) $ 2\int_0^{a}{\frac{1}{1+x^{3}}\ }dx $

D) $ \int_0^{a}{\frac{1}{1+{{(a-x)}^{3}}}\ }dx $

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Answer:

Correct Answer: A

Solution:

Since $ \int _{-a}^{a}{f(x)}\ dx=0 $ ,if $ f(-x)=-f(x) $

Therefore, $ \int _{-a}^{a}{\frac{dx}{x+x^{3}}}=0 $ .