Hey there! Sign in to join this conversationNew here? Join for free
 You are Here: Home >< Maths

Implicit Differentiation Watch

1. Hey,

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 ]
2. 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".

Reply
Submit reply
TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

This forum is supported by:
Updated: April 19, 2013
Today on TSR

Last-minute PS help

100s of personal statements examples here

Loneliness at uni

Discussions on TSR

• Latest
• See more of what you like on The Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

• Poll
Useful resources

Make your revision easier

Maths Forum posting guidelines

Not sure where to post? Read the updated guidelines here

How to use LaTex

Writing equations the easy way

Study habits of A* students

Top tips from students who have already aced their exams

Create your own Study Planner

Never miss a deadline again

Thinking about a maths degree?

Chat with other maths applicants

Can you help? Study help unanswered threads

Groups associated with this forum:

View associated groups
Discussions on TSR

• Latest
• See more of what you like on The Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

• The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE

Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.