Target Exam

CUET

Subject

-- Applied Mathematics - Section B2

Chapter

Calculus

Question:

If $y = log_e \left(\frac{x^3}{e^3}\right),$ then $\frac{d^2y}{dx^2} $ is equal to

Options:

$\frac{3}{x^2}$

$-\frac{2}{x^2}$

$-\frac{3}{x^2}$

$-\frac{2}{x}$

Correct Answer:

$-\frac{3}{x^2}$

Explanation:

The correct answer is Option (3) → $-\frac{3}{x^2}$

$y=\log_e\left(\frac{x^3}{e^3}\right)$  [Given]

$\frac{dy}{dx}=\frac{e^3}{x^3}×\frac{3x^2}{e^3}=\frac{3}{x}$

$⇒\frac{d^2y}{dx^2}=-\frac{3}{x^2}$