Find dydxin the following questions:
x2+xy+y2=100
Given, x2+xy+y2=100
Differentiating both sides w.r.t. x, we get
ddx(x2+xy+y)=0 ⇒ 2x+(xdydx+y.1)+2ydydx=0 (Using product ruleddx(u.v)=uddxv+vddxu)
⇒ dydx(x+2y)=−2x−y ⇒ dydx=−2x+yx+2y
x2+x2y+xy2+y3=81.