Question

Differentiation of $\frac{-x^3}{3}$ w.r.t $x$ is

• A. $x^2$
• B. $-x^2$
• C. $-3x^2$
• D. $3x^2$

Answer 1

The correct option is B $-x^2$

Given, $f\left(x\right)=\frac{-x^3}{3}$
So, $\frac{df\left(x\right)}{dx}=\frac{d\left(\frac{-x^3}{3}\right)}{dx}=\frac{-1}{3}\frac{d{x}^3}{dx}$
$\Rightarrow \frac{-1}{3}\left(3x^2\right)=-x^2$