Here's the question:

Verify by substitution that is a solution to

I decided to do this question by differentiating y twice (to get and ) and subsituting these expressions in. Then I would rearrange the equation to make y the subject and prove that what I get is .

After substituting these expressions in I end up with:

.

I just wanted to check if my differentiation was correct. I have double and triple checked my substitution and that's fine.

It just occurred to be that I should have put this in the calculus section. Sorry!