x Turn on thread page Beta
 You are Here: Home >< Maths

# Continuous functions question watch

1. These questions are the bane of my life...

at c=2

So far I've got...

Then restricting x by requiringso,

This is where I get stuck... I'm not sure how to add on the "+2x" to get to x^2 + 2x + 4? Thanks for any help
2. Firstly, simplify your life by realising that you just want to find an upper bound for x^2+2x+4 (for x in range 1 < x < 3).

So if you find upper bounds for x^2, 2x and 4, you can just add them to get an upper bound for x^2+2x+4.

You've already done x^2: if 1 < x < 3, we have x^2 < 9.

Do the same for the other two bits and add.
3. (Original post by DFranklin)
Firstly, simplify your life by realising that you just want to find an upper bound for x^2+2x+4 (for x in range 1 < x < 3).

So if you find upper bounds for x^2, 2x and 4, you can just add them to get an upper bound for x^2+2x+4.

You've already done x^2: if 1 < x < 3, we have x^2 < 9.

Do the same for the other two bits and add.
Ahh thankyou so much, didn't even think of doing it separately like that I was just trying to do it in the one go haha. And I will simplify my life by not choosing analysis next year

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: January 16, 2015
Today on TSR

### University rankings 2019

Cambridge at number one

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