Implicit Differentiation (2.5 # 35, 37, 39)

 Implicit Differentiation (2.5 # 35, 37, 39)

We don't need to "solve for y" before we take a derivative.  This allows us to handle relationships that are not functions like these three examples.  The only thing to be mindful of it to use the chain rule! 

Do a derivative of y^2 is not merely 2y, it it 2y*(dy/dx) or if you like 2y*y'.