Target Exam

CUET

Subject

-- Mathematics - Section B1

Chapter

Applications of Derivatives

Question:

The equation of normal to the curve $2 y+x^2=3$ at the point $(1,1)$ is:

Options:

$x+y=0$

$x-y=0$

$x+y+1=0$

$x-y=1$

Correct Answer:

$x-y=0$

Explanation:

The correct answer is Option (2) → $x-y=0$

$2 y+x^2=3$

differentiating w.r.t. x

$⇒\frac{2dy}{dx}+2x=3⇒\frac{dy}{dx}=-x$

⇒ Slope of normal = $\frac{1}{x}$

$\left.\frac{1}{x}\right]_{(1,1)}=1$

so equation of normal

$y-1=x-1$

so $x-y=0$