Target Exam

CUET

Subject

-- Applied Mathematics - Section B2

Chapter

Calculus

Question:

If $x=at^2 $ and $y = a^3t^3 ,$ then $\frac{d^2y}{dx^2}$ will be :

Options:

$\frac{3at}{2}$

$\frac{3}{4at}$

$\frac{3a}{4t}$

$\frac{3a^2t}{2}$

Correct Answer:

$\frac{3a}{4t}$

Explanation:

The correct answer is Option (3) → $\frac{3a}{4t}$

$\frac{dx}{dt}=2at$

$\frac{dy}{dt} = 3a^3t^2$

$\frac{dy}{dx}=\frac{3a^3t^2}{2at}=\frac{3a^2t}{2}$

$\frac{d^2y}{dx^2}=\frac{3a^2}{t}\frac{dt}{dx}=\frac{3a^2}{2×2at}=\frac{3a}{4t}$