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

# I need someone to explain why? watch

1. Struggling to make sense of this past paper question (Question 12 (ii) onwards).

http://vle.woodhouse.ac.uk/topicdocs...010January.pdf

I want to understand why this works - I've seen the mark scheme and know the answers, but would like someone to explain it to me in "writing" terms

Thanks
2. Its an x^2 parabola. So its symmetric. If we know the two points of same y, the max/min y will be inbetween those two points.

The height is just putting in the x-vlaue.
3. (Original post by jamescbsmith)
Struggling to make sense of this past paper question (Question 12 (ii) onwards).

So that is how you can easily do (ii)

Then, of course finding d is obvious

So you use d as x to find y, then y will be more than 4 so that is (iii) finished

For (iv) you know y so you can find x then use symmetry again to give x+width+x = 10 to find the width
4. (Original post by TenOfThem)

So that is how you can easily do (ii)

So you use d as x to find y, then y will be more than 4 so that is (iii) finished

For (iv) you know y so you can find x then use symmetry again to give x+width+x = 10 to find the width
Could you elaborate on what you mean by symmetry please? (gosh I feel silly asking)
5. (Original post by jamescbsmith)
Could you elaborate on what you mean by symmetry please? (gosh I feel silly asking)
There is a line of reflection symmetry through the vertex
6. (Original post by TenOfThem)
There is a line of reflection symmetry through the vertex
Ah I think I understand - so for (ii) all I really had to do is divide 10 by 2 to get x=5 as x^2 is a parabola and there is symmetry about the vertex!
Thanks to you both!

Turn on thread page Beta
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 5, 2013
Today on TSR

### Which business legend are you?

We have the answer...

### University open days

• University of Bradford
Wed, 21 Nov '18
• Buckinghamshire New University
Wed, 21 Nov '18
• Heriot-Watt University
Wed, 21 Nov '18
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

Can you help? Study help unanswered threads

## Groups associated with this forum:

View associated groups

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