Target Exam

CUET

Subject

Section B1

Chapter

Continuity and Differentiability

Question:

If $x = A \cos 4t + B \sin 4t$, then $\frac{d^2x}{dt^2}$ is equal to:

Options:

$x$

$-x$

$16x$

$-16x$

Correct Answer:

$-16x$

Explanation:

The correct answer is Option (4) → $-16x$ ##

$x = A \cos 4t + B \sin 4t$

$\frac{dx}{dt} = -4A \sin 4t + 4B \cos 4t$

$\frac{d^2x}{dt^2} = -16A \cos 4t - 16B \sin 4t$

$= -16(A \cos 4t + B \sin 4t)$

$∴\frac{d^2x}{dt^2} = -16x$