Question

If $x^2+y^2=4$, then $y\frac{dy}{dx}+x=$

• A. 4
• B. 0
• C. 1
• D. -1

Answer 1

Answer: (B)

Given, $x^2+y^2=4$
On differentiating w.r.t. $x$, we get
$2x+2y\frac{dy}{dx}=0$
$\Rightarrow y\frac{dy}{dx}+x=0$