Question

If $\int \frac{dx}{\sqrt{a^2-x^2}}={\sin }^{-1}\frac{x}{3}+c$, then $a=$

• A. 3
• B. 4
• C. 6
• D. 8

Answer 1

Answer: (A)

$\because \int \frac{dx}{\sqrt{a^2-x^2}}={\sin }^{-1}\frac{x}{a}+c$
But it is given that $\int \frac{dx}{\sqrt{a^2-x^2}}={\sin }^{-1}\frac{x}{3}+c$