Target Exam

CUET

Subject

-- Applied Mathematics - Section B2

Chapter

Calculus

Question:

Solution of the differential equation $x\, dy - y\, dx = 0 $ represents

Options:

a rectangular hyperbola

a straight line passing through the origin

parabola whose vertex is at origin

circle whose centre is at the origin

Correct Answer:

a straight line passing through the origin

Explanation:

The correct answer is option (2) : a straight line passing through the origin

We have,

$x\, dy - y \, dx = 0 $

$⇒\frac{1}{y}dy-\frac{1}{x}dx=0$

$⇒log\, y - log\, x - log\, C$  {On integrating]

$⇒\frac{y}{x}= C⇒y = Cx $

Clearly, it represents a straight line passing through the origin.