Integral Calculus Question 448

Question: The value of $ \int_{{}}^{{}}{\frac{dx}{\sqrt{1-x}}} $ is

[Pb. CET 2001]

Options:

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

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

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

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

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Answer:

Correct Answer: B

Solution:

We have, $ \int_{{}}^{{}}{\frac{dx}{\sqrt{1-x}}} $ or $ I=\int_{{}}^{{}}{{{(1-x)}^{-1/2}}dx} $ $ I=\frac{{{(1-x)}^{\frac{-1}{2}+1}}}{(-1),( -\frac{1}{2}+1 )}+c $
Þ $ I=-2\sqrt{1-x}+c $ .