Target Exam

CUET

Subject

-- Applied Mathematics - Section B2

Chapter

Calculus

Question:

If $y=36 e^{5 x}+47 e^{-5 x}$, then

Options:

$\frac{d^2 y}{d x^2}=-25 y$

$\frac{d^2 y}{d x^2}=5 y$

$\frac{d^2 y}{d x^2}=-5 y$

$\frac{d^2 y}{d x^2}=25 y$

Correct Answer:

$\frac{d^2 y}{d x^2}=25 y$

Explanation:

The correct answer is Option () - 

$y=36e^{5x}+47e^{-5x}.$

$\frac{dy}{dx}=36\cdot5e^{5x}-47\cdot5e^{-5x}=180e^{5x}-235e^{-5x}.$

$\frac{d^2y}{dx^2}=180\cdot5e^{5x}+235\cdot5e^{-5x}=900e^{5x}+1175e^{-5x}.$

$\frac{d^2y}{dx^2}=25(36e^{5x}+47e^{-5x}).$

$\frac{d^2y}{dx^2}=25y.$