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

# c1 help! Watch

1. hello,

can someone tell me what it is x+y =8 cuts the y-axis please can someone tell me the answer please thank you so much
2. (Original post by otrivine)
hello,

can someone tell me what it is x+y =8 cuts the y-axis please can someone tell me the answer please thank you so much
It cuts the y axis at (0,8)

rearrange equation to give y = 8-x

which is in form of y = mx + c
where c is the y intercept

so c = 8
3. i got it hanks you for your help
4. for example if they say 2x+y=8 cuts the x-aixs do you say

y=8/2x and the co-ordinate is (4,0)
5. (Original post by otrivine)
i got it hanks you for your help
another way to look at it (which is how you must look at it when sketching curves, very important) is that when it cuts the y-axis, the x-value must be zero. So you sub in zero into all the x's in the formula to get the y-intercept
6. brilliant thank you so much for your help ilyking
7. Just substitute y=0 (if looking where it intercepts x axis) or x=0 (if looking where it intercepts y axis) into the equation.
8. what does this question mean :- the line crosses the x-axis and the point A and the y-axis at the point B , and O is the origin find the area of triangle A,B,C and the only to co-ordinates which i am given is (-1,5) (4,-2)
9. please answer soebody
10. A(-1,-2)B(7,2)C(K,4) work out K?
11. please anyone answer 1!!!1
12. (Original post by otrivine)
what does this question mean :- the line crosses the x-axis and the point A and the y-axis at the point B , and O is the origin find the area of triangle A,B,C and the only to co-ordinates which i am given is (-1,5) (4,-2)
work out the equation of the line that passes through those two co-ordinates (-1,5) (4,-2) and then use the equation to find out where it crosses the x and y axis. after that you have a triangle so you can work out the area. inbox me if you need any help
13. can someone tell me what is the grade boundaire for C1 edexcel january 2007? thank you
14. (Original post by otrivine)
can someone tell me what is the grade boundaire for C1 edexcel january 2007? thank you
Not low enough to help you I fear....
15. (Original post by otrivine)
can someone tell me what is the grade boundaire for C1 edexcel january 2007? thank you
Try to focus on getting better at answering the questions first - without stressing about grade boundaries :P Try to actually think about the question and ways to answer them because in the exam there won't be TSR to help you. As to your triangle question, plotting the points on a graph may really help you. Then as someone already said, you'll probably need to find the equation of the lines.

--------------

If you don't know how to find the equation of a straight line given two points, here is one example:

Points A (1, 5) and B (5, 3) are two points on a straight line. Find the equation of the line in the form y=mx+c

First find the gradient, m, which is basically change in y divided by change in x.
For this example, that would be

Plop this into y=mx+c to give you y=-0.5x+c
Now we need to find c. Pick any point they give you - i'm gonna pick A (1, 5) - and substitute the values in:

5=-0.5(1)+c
5=-0.5+c
c=5.5

So plop this into y=-0.5x+c and you'll get y=-0.5x+5.5 as the equation of the line.

Find where AB crosses the y axis

y=-0.5x+5.5

Let x=0
y=-0.5(0)+5.5
y=5.5

AB crosses the y axis at (0, 5.5)

--------------

(Original post by AnHuman)
Not low enough to help you I fear....
That's not too nice lol

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: December 24, 2010
Today on TSR

### Medicine, fastest and slowest offer senders

Have you got yours?

### You can apply to Hogwarts?!

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

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.