Integral Calculus Question 491

Question: $ \int_{{}}^{{}}{\sqrt{\frac{1-x}{1+x}}}\ dx= $

[IIT 1971]

Options:

A) $ {{\sin }^{-1}}x-\frac{1}{2}\sqrt{1-x^{2}}+c $

B) $ {{\sin }^{-1}}x+\frac{1}{2}\sqrt{1-x^{2}}+c $

C) $ {{\sin }^{-1}}x-\sqrt{1-x^{2}}+c $

D) $ {{\sin }^{-1}}x+\sqrt{1-x^{2}}+c $

Show Answer

Answer:

Correct Answer: D

Solution:

$ \int_{{}}^{{}}{\sqrt{\frac{1-x}{1+x}},dx}=\int_{{}}^{{}}{\frac{1-x}{\sqrt{1-x^{2}}}},dx=\int_{{}}^{{}}{\frac{1}{\sqrt{1-x^{2}}}},dx-\int_{{}}^{{}}{\frac{x,dx}{\sqrt{1-x^{2}}}} $ Now proceed yourself.