It says in this book that dy/dx = (-dy/dx) / (dy/dy)
But doesn't that equal dy/dx = -dy/dx?
And when I do it the way I learnt for C4, I obtain the positive answer (i.e. not with the minus).
Slightly confused, can anyone help?
EDIT: No worries, I've got the right answer, and I understand why it works I think lol. It's because you take the non-dy/dx terms to the other side. Right?
[And, okay I just realised I read it wrong :/ (that wasn't a 'y', it was a 'g'), bloody fonts these days ]
Implicit Differentiation Watch
- Thread Starter
Last edited by COD_is_a_fish; 19-04-2013 at 15:41.
- 19-04-2013 15:31
- 19-04-2013 19:34
Well, the formula is true. There's a proof (of sorts) on this page here. I don't fully follow it myself, so best of luck.
I found this page by googling on "Implicit function theorem differentiation".