# Math Help - implicit differentiation

1. ## implicit differentiation

how do i find dy/dx? where y = cos (xy^2) could i say dy/dx = -sin (xy^2) times the derivative of the inside stuff? with respect to x. i suppose i would use the product rule? right or is there an easier way to do this problem?

2. Hello, slapmaxwell1!

How do i find $\frac{dy}{dx}\,\text{ where }\,y \:=\: \cos(xy^2)$

Could i say: . $\frac{dy}{dx} \:=\: -\sin(xy^2)$ .times the derivative of the inside stuff with respect to x? . Yes!

i suppose i would use the product rule, right? . Right!

or is there an easier way to do this problem? . I don't think so.

You'd have: . $\frac{dy}{dx} \;=\;-\sin(xy^2)\cdot\bigg[x\cdot2y\frac{dy}{dx} + y^2\bigg]$

Then solve for $\frac{dy}{dx}$ . . . carefully.

3. i will definitely take my time, thanks again, once i finish this problem i get to review washers and disc's?? looks i will be here tonight. lol