Target Exam

CUET

Subject

-- Applied Mathematics - Section B2

Chapter

Calculus

Question:

Match List-I with List-II

List-I (Parametric equations)

List-II $(\frac{dy}{dx})$

(A) $x =\frac{2}{t},y=2t$

(I) $4t^2$

(B) $x=t^3,y=3t+ 2$

(II) $2(t+1)$

(C) $x = \log t,y=2t^2$

(III) $-t^2$

(D) $x = e^t,y=2te^t$

(IV) $t^{-2}$

Choose the correct answer from the options given below:

Options:

(A)-(I), (B)-(II), (C)-(III), (D)-(IV)

(A)-(II), (B)-(I), (C)-(III), (D)-(IV)

(A)-(IV), (B)-(III), (C)-(I), (D)-(II)

(A)-(III), (B)-(IV), (C)-(I), (D)-(II)

Correct Answer:

(A)-(III), (B)-(IV), (C)-(I), (D)-(II)

Explanation:

The correct answer is Option (4) → (A)-(III), (B)-(IV), (C)-(I), (D)-(II)

List-I (Parametric equations)

List-II $(\frac{dy}{dx})$

(A) $x =\frac{2}{t},y=2t$

(III) $-t^2$

(B) $x=t^3,y=3t+ 2$

(IV) $t^{-2}$

(C) $x = \log t,y=2t^2$

(I) $4t^2$

(D) $x = e^t,y=2te^t$

(II) $2(t+1)$

(A) $x=\frac{2}{t},\; y=2t$

$\frac{dx}{dt}=-\frac{2}{t^2},\;\frac{dy}{dt}=2$

$\frac{dy}{dx}=\frac{2}{-2/t^2}=-t^2 \;\;\;\Rightarrow\;$ (III)

(B) $x=t^3,\; y=3t+2$

$\frac{dx}{dt}=3t^2,\;\frac{dy}{dt}=3$

$\frac{dy}{dx}=\frac{3}{3t^2}=\frac{1}{t^2} \;\;\;\Rightarrow\;$ (IV)

(C) $x=\log t,\; y=2t^2$

$\frac{dx}{dt}=\frac{1}{t},\;\frac{dy}{dt}=4t$

$\frac{dy}{dx}=\frac{4t}{1/t}=4t^2 \;\;\;\Rightarrow\;$ (I)

(D) $x=e^t,\; y=2te^t$

$\frac{dx}{dt}=e^t,\;\frac{dy}{dt}=2e^t+2te^t=2(t+1)e^t$

$\frac{dy}{dx}=\frac{2(t+1)e^t}{e^t}=2(t+1) \;\;\;\Rightarrow\;$ (II)