Question

If $\int f\left(x\right)dx=-2\cos \sqrt{x}+c$ then $f\left(x\right)$ is equal to

• A. $\sin \sqrt{x}$
• B. $\frac{\sin \sqrt{x}}{\sqrt{x}}$
• C. $2\cos \sqrt{x}$
• D. None of these

Answer 1

The correct option is B $\frac{\sin \sqrt{x}}{\sqrt{x}}$

$\int f\left(x\right)dx=-2\cos \sqrt{x}+c$
$f\left(x\right)=\frac{d(-2\cos \sqrt{x})}{dx}=\frac{\sin \sqrt{x}}{\sqrt{x}}$