CUET Preparation Today
CUET
Section B1
Continuity and Differentiability
If $y = x|x|$, find $\frac{dy}{dx}$ for $x < 0$.
$2x$
$-2x$
$x$
$-x$
The correct answer is Option (2) → $-2x$ ##
For $x < 0$, $y=x|x| = -x^2$
$∴\frac{dy}{dx} = -2x$