Question

The value of ${\int }_0^1\frac{dx}{\sqrt{1-x^2}}$ is

• A. $\pi /3$
• B. $\pi /2$
• C. $1/2$
• D. $\pi /4$

Answer 1

The correct option is B $\pi /2$

Now,

${\int }_0^1\frac{dx}{\sqrt{1-x^2}}$

$={\left[{\sin }^{-1}x\right]}_0^1$

$=\frac{\pi }{2}$.