You are Here: Home >< Maths

# OCR Maths Core 3 question!

The very very last question please 9iii) where it says show that the gradient is -1

i'm up to the point where i've got x^4-5x^2+100=0

but what do I do from there?
2. Try substituting x^2 for u, the rest ought to become clear.
3. Set dy/dx as -1 and then move that over to the other side to make dy/dx=0. Then work out the discriminant and it should be negative - meaning no real roots.

And btw - its asking you to show the gradient is NEVER -1

## Register

Thanks for posting! You just need to create an account in order to submit the post
1. this can't be left blank
2. this can't be left blank
3. this can't be left blank

6 characters or longer with both numbers and letters is safer

4. this can't be left empty
1. Oops, you need to agree to our Ts&Cs to register

Updated: June 9, 2012
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:
Today on TSR

### A-level exams coming up?

Find everything you need here.

Poll
Useful resources

### 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