Target Exam

CUET

Subject

-- Mathematics - Section B1

Chapter

Differential Equations

Question:

Match List-I with List-II

List-I

List-II

(A) The degree of the differential equation $\left(\frac{d^2y}{dx^2}\right)^2 + \left(\frac{dy}{dx}\right)^2 = x\sin\left(\frac{dy}{dx}\right)$

(I) 4

(B) The degree of differential equation $\frac{d^2y}{dx^2}+\left(\frac{dy}{dx}\right)^{1/4}+x^{1/5}=0$

(II) 1

(C) The degree of differential equation $\frac{d^2y}{dx^2}\left(\frac{dy}{dx}\right)^3+6y^5=0$

(III) Not defined

(D) The degree of differential equation $1+\left(\frac{dy}{dx}\right)^4=7\left(\frac{d^2y}{dx^2}\right)^3$

(IV) 3

Choose the correct answer from the options given below:

Options:

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

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

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

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

Correct Answer:

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

Explanation:

The correct answer is Option (2) → (A)-(III), (B)-(I), (C)-(II), (D)-(IV)

Explanation:

Matching List-I with List-II:

(A) The degree of the differential equation $ \left( \frac{d^2 y}{dx^2} \right)^2 + \left( \frac{dy}{dx} \right)^2 = x \sin\left( \frac{dy}{dx} \right) $
→ Highest order derivative is $ \frac{d^2 y}{dx^2} $ raised to power 2, and the equation is polynomial in derivatives.
Degree = 2 but RHS involves $ \sin\left( \frac{dy}{dx} \right) $, so it is not polynomial in derivatives.
Degree is Not defined ⇒ (III)

(B) $ \frac{d^2 y}{dx^2} + \left( \frac{dy}{dx} \right)^{1/4} + x^{1/5} = 0 $
→ $\frac{dy}{dx} =( \frac{d^2 y}{dx^2}+ x^{1/5})^{4}$
Degree is 4 since $ \frac{d^2 y}{dx^2} $ degree is 4 → (I)

(C) $ \frac{d^2 y}{dx^2} \left( \frac{dy}{dx} \right)^3 + 6y^5 = 0 $
→ Highest derivative: $ \frac{d^2 y}{dx^2} $ raised to power 1 and equation is polynomial
Degree = 1 ⇒ (II)

(D) $ 1 + \left( \frac{dy}{dx} \right)^4 = 7 \left( \frac{d^2 y}{dx^2} \right)^3 $
→ Highest derivative: $ \frac{d^2 y}{dx^2} $ raised to power 3
Degree = 3 ⇒ (IV)