The function $f(x) = x^2e^{-2x}$ increases on
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → $(0,1)$
Given: $f(x) = x^{2} e^{-2x}$
Differentiate:
$f'(x) = e^{-2x}(2x - 2x^{2}) = 2x e^{-2x}(1 - x)$
Since $e^{-2x} > 0$ for all $x$, the sign of $f'(x)$ depends on $2x(1 - x)$.
$f'(x) > 0 \Rightarrow 2x(1 - x) > 0$
This holds when $x \in (0, 1)$.
Therefore, the function increases on $(0, 1)$.