So, i have no problem finding the first derivative. But then i cant get my answer to match the books answer for the second derivative. How are they getting the highlighted area? It doesnt look like they used the Quotient Rule. Have they moved the denominator up and then power rule?
Thanks for the help.
The differentiation of the first term is not correct: you differentiating x^2*y correctly but not the other one.
So d/dx[x^2*y*y']
= 2xyy' + x^2[d/dx](yy')
= 2xyy' + x^2[y'y' + y*y'']
= 2xyy' + x^2[y']^2 + x^2[yy'']
Try using this and see how you go.