You are Here: Home >< A-levels

# C1 help pls watch

1. Attachment 608138hello

HOW THE HELL DID THEY GET CO-ORDINATE B as (7,0)??????
2. (Original post by CorpusLuteum)
Attachment 608138hello

HOW THE HELL DID THEY GET CO-ORDINATE B as (7,0)??????
3. the attachment doesnt work
4. (Original post by Maz A)
(Original post by gaary kasparov)
the attachment doesnt work
it worked above now right
5. not done that in edexcel c1. we only just started c2 so cant help you. sorry.
6. (Original post by CorpusLuteum)
ez question lel

well you're gonna make an isoceles triangle aren't you? with lines CA and CB equalling each other, in other words CA=CB
7. (Original post by will'o'wisp)
ez question lel

well you're gonna make an isoceles triangle aren't you? With lines ca and cb equalling each other, in other words ca=cb
but its one mark?
8. (Original post by CorpusLuteum)
it worked above now right
ABC is an equilateral triangle, so the length of AC = CB. Difference in x coordinates from A to C is 3 (4-1) so the difference in x coordinates between C and B will be the same, so it's 4+3=7.
9. (Original post by CorpusLuteum)
Find the radius length from the distance between A and C, use that to find the equation of the circle and then equate to the x axis and solve
Or, what's probably easier is looking at how A and B are equidistant from C. In the x axis, A is 3 from C. B must be 3 from C, and 4 (the centre x coordinate) +3 is 7
10. (Original post by CorpusLuteum)
but its one mark?
mmhm

That's what you should be thinking.

No matter how you place the circle the distance from the centre of the circle to the points where the circle touches the x-axis will be exactly the same length.

When you realise this you can see the difference in x-values for C and A 4-1=3 so 3 is the difference between the x-coord of the centre and the first point where the circle touches the x-axis. The distance will therefore be the same from the x-coord of the centre to B

In other words CA=CB

I'm sure there's a circle theorem which says if you draw a chord and draw 2 lines from either end of the chord to the centre of the circle then you get isosceles triangle.

With a little bit of thinking it's the 3rd picture on the left from top to bottom
11. I think because point C is in the centre of the circle, you know that points A and B are of equal distances from C. You already know the y coordinate which is 0 and you find out the x coordinate by finding the difference between the x coordinate of A and C and adding it on to 4 which is 7. If I'm correct, the answer will be (7, 0)

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 3, 2017
Today on TSR

### Summer Bucket List is Back!

Start yours and you could win £150!

Poll

## All the essentials

### Student life: what to expect

What it's really like going to uni

### Essay expert

Learn to write like a pro with our ultimate essay guide.

### Create a study plan

Get your head around what you need to do and when with the study planner tool.

### Resources by subject

Everything from mind maps to class notes.

### Study tips from A* students

Students who got top grades in their A-levels share their secrets