# Straight Line Graphs

Straight line graphs are all of the form y=mx+c. In this, y is the y-co-ordinate, x is the x-co-ordinate, m is the gradient and c is the y-intercept. Once you have this information, you can calculate the equation of a line, the equation of a line that runs perpendicular to your graph through a particular point, the equation of a line that runs parallel to your graph through a particular point. you can also use this equation to find if any co-ordinates are on the graph line in question.

## Identify the gradient and intercept

From a series of equations, identify the gradient and the intercept of each graph. In addition to this, when provided with the gradient and intercept, construct the equation of the graph.

## GCSE Exam questions on Graphs

GCSE Exam questions on Graphs. Includes the mark scheme so print pages 1-27 for the examination questions only.

## 20 Question cards on linear graphs

20 Question cards on linear graphs. If you print out three of each card, it should keep a class of children busy for a lesson or two.

## Drawing a straight line graph video

Drawing a straight line graph video for Foundation GCSE mathematics.

## Finding the equation of a graph video

Finding the equation of a graph video.

## Finding the equation of a perpendicular line

Once you have the original equation of a graph, you can calculate the gradient of a perpendicular line by finding the reciprocal of minus the gradient of the original graph. This video shows you how.

## Easier version of finding the equation for a graph

Find the equation of a graph by finding two points on the graph and calculating the gradient from those. In this version, you just look at the graph to find the y-intercept. It is a good introduction to straight line graphs but you need to do more for GCSE. The sheets that I used in this can be found here: sheet 1, sheet 2,sheet 3,sheet 4,sheet 5

Find the gradients of various linear graphs in order to practise for GCSE mathematics.

Solutions for the work in Gradients 1.

Calculate the gradient of a line given two points on the line.

## Formulae from lines on a graph

Find the co-ordinates of two points and work out the gradient. Move on to work out the intercept to finalise your formula.

## Help sheet for calculating the equation of a line

Help sheet for calculating the equation of a line. I have tried to point out some of the pitfalls on this sheet in order that the students might avoid them.

## Equation of a graph 1

An introduction to finding the equation of a graph line. A video showing you what to do can be found here.

## Equation of a graph 2

Further practice on the introduction to finding the equation of a graph line. A video showing you what to do can be found here.

## Equation of a graph 3

Further practice on the introduction to finding the equation of a graph line. A video showing you what to do can be found here.

## Equation of a graph 4

Further practice on the introduction to finding the equation of a graph line. A video showing you what to do can be found here.

## Equation of a graph 5

Further practice on the introduction to finding the equation of a graph line. A video showing you what to do can be found here.

## Plotting graphs

Calculate the values of x for given values of y for a given equation between two limits and then plot the graph.

Calculate the equation of a graph from seeing it, from two co-ordinates, from one co-ordinate and a gradient, from a parallel graph and a co-ordinate.

## Formulae of Vertical and Horizontal lines

Label each line on the graph paper with its equation. Remember that vertical lines are x= something and horizontal lines are y= something.

## Find values of y between -8 and 8

Substitute the values of -8 to 8 into x to find the value or y. Draw the graphs.

Maths intervention on gradients talking the student through each stage.

## Video of equation of parallel line going through a point

Calculate the equation of a line parallel to anther one that goes through a point. Remember that parallel lines have the same gradient.

## Calculating coordinates for a straight line

Given an equation and the limits, calculate the y co-ordinate for each x co-ordinate between the limits.