Implicit Differentiation with Sin

[Pondera]

Homework Statement

Homework Equations

The Attempt at a Solution

 

[jgens]

It looks like you're not applying the product rule properly when differentiating xy^2. d(xy^2) = y^2 + 2xyy'

 

[Pondera]

I wasn't using the product rule at all. Thank you for that! Haha.

I tried it again and got:

Line by line:
7= cos(xy^2)(y^2+2xyy')
7/ cos(xy^2) = (y^2+2xyy')
7/ cos(xy^2) - y^2 = 2xyy'
(7/ cos(xy^2) - y^2)(2xy) = y'

 

[gabbagabbahey]

On your last step, why are you multiplying by 2xy?...Shouldn't you be dividing instead?

 

[Pondera]

Yeah, it should be divided by our multiplied by (1/2xy). I'm not sure why I did that. :P

The rest of it looks okay though?

 

[gabbagabbahey]

the rest looks fine

 

[Pondera]

WOOO! It was right! Thank you very much, jgens and gabba.