Maths

>

GCSE

>

Plot and Interpret Graphs

>

How do you...

Question
# How do you draw a straight-line graph using y = mx + c ?

3 years ago

·

2 Replies

·

3340 views

S

Shania Cruickshank

2 Answers

Lissie
Verified Sherpa Tutor ✓

Experienced Maths tutor, infectiously enthusiastic

m represents the gradient

c represents the y axis intercept (where the graph crosses the y axis)

Start by plotting the point (0,c) which your line passes through

Then plot a second point using the gradient..

e.g. if m = 2 then increasing x by 1 increases y by 2, so (1, c+2) will be your next point on the graph

Plot a line through these points

Remember that negative gradient means an increase of 1 for x causes a *decrease* of m for y

I'm available for 1:1 private online tuition!

Click here to view my profile and arrange a free introduction.
D

Dawn M

First mark the point where the line will cross the y axis which is at y = c.

Then the gradient m tells you which way your line should slope and also how many to go up or down for every 1 unit across. If m is positive the lines slopes like this / and if it is negative it slopes like this \.

To plot the line, first plot a second point starting from the first point you marked at y = c. You do this by going across one unit horizontally and if m is + then you go up by m units and if m is - you go down by m units.

Once you have your second point it is worth repeating the process to get a third point for safety and then you can draw a line that goes through all 3 points.

Example: y = 2x + 3

First point will be (0, 3)

Next point will be (1, 3+2) = (1, 5)

Next point will be (2, 5 + 2) = (2, 7)

Think you can help?

More Maths GCSE Questions
##
Need
a GCSE
Maths
tutor?

Get started with a free online introductions with an experienced and qualified online tutor on Sherpa.

Find a GCSE Maths Tutor