Practicing Success

Target Exam

CUET

Subject

-- Mathematics - Section B1

Chapter

Differential Equations

Question:

The order and degree the differential equation of all tangent lines to the parabola $x^2=4 y$, is

Options:

2, 1

2, 2

3, 1

4, 1

Correct Answer:

2, 1

Explanation:

$x^2=4y⇒\frac{dy}{dx}=\frac{x}{2}$

so equation of tangent

$(y-y_0)=\frac{x}{2}(x-x_0)$

so $2(y-y_0)=x^2-x_0x$

differentiating wrt x

$2y'=2x-x_0$

again differentiating wrt x

so $2y''=2$ so $y''=1$

order → 2, degree → 1