Target Exam

CUET

Subject

-- Mathematics - Section A

Chapter

Applications of Derivatives

Question:

If $y = 5e^{2x}+4e^{3x}$, then $\frac{d^2y}{dx^2}$ equals:

Options:

$3(2e^{2x}+6e^{3x})$

$4(5e^{2x}+9e^{3x})$

$5(4e^{2x}+9e^{3x})$

$2(5e^{2x}+8e^{3x})$

Correct Answer:

$4(5e^{2x}+9e^{3x})$

Explanation:

The correct answer is Option (2) → $4(5e^{2x}+9e^{3x})$

Given: $y = 5e^{2x} + 4e^{3x}$

First derivative:

$\frac{dy}{dx} = 5 \cdot 2e^{2x} + 4 \cdot 3e^{3x} = 10e^{2x} + 12e^{3x}$

Second derivative:

$\frac{d^2y}{dx^2} = 10 \cdot 2e^{2x} + 12 \cdot 3e^{3x} = 20e^{2x} + 36e^{3x}$