Practicing Success

Target Exam

CUET

Subject

-- Mathematics - Section B1

Chapter

Differential Equations

Question:

A curve having the condition that the slope of the tangent at some point is two times the slope of the straight line joining the same point to the origin of coordinates is a / an

Options:

circle

ellipse

parabola

hyperbola

Correct Answer:

parabola

Explanation:

Let $P(x, y)$ be any point on the curve. Then,

$\frac{d y}{d x}=2\left(\frac{y-0}{x-0}\right)$

$\Rightarrow \frac{1}{y} d y =\frac{2}{x} d x$

$\Rightarrow \log y=2 \log x+\log C \Rightarrow y=C x^2$         .....(i)

Clearly, it is a parabola.