Target Exam

CUET

Subject

-- Mathematics - Section A

Chapter

Differential Equations

Question:

The solution of the differential equation $\frac{dy}{dx}=\frac{6}{x^2}$; y(1) = 3 is:

Options:

$y=9+\frac{6}{x}$

$y=9-\frac{6}{x}$

$y=-9+\frac{6}{x}$

$y=-3-\frac{6}{x}$

Correct Answer:

$y=9-\frac{6}{x}$

Explanation:

The correct answer is Option (2) - $y=9-\frac{6}{x}$

$\frac{dy}{dx}=\frac{6}{x^2}⇒\int dy=\frac{6}{x^2}dx$

$y=-\frac{6}{x}+C$

as $y(1)=3⇒3=-6+C$

$⇒C=9$

so $y=9-\frac{6}{x}$