# gradient and y-intercept

```• On boards, draw a set of axes from -5 to 5 in both the x and y directions
• In your pairs, label yourselves A and B
• Person A needs to draw a line graph on their axes without showing
person B
• Now person A describes the line graph to person B, who draws the graph
from the description
• Once done, check that the two graphs match
• If they do, sketch the graph and description given on a piece of square
paper
• If they don’t, as a pair work out what went wrong, and sketch the
correct graph with a correct description on a piece of square paper
• Repeat the process, swapping roles.
What information do we need to
describe a line accurately?
The y-intercept and the gradient
Objective: To recognise and use the y-intercept
and the gradient of a graph.
Find the gradient and y-intercept of the straight-line graph.
(4,6)
8
(0,-2)
4
Find the gradient and y-intercept of the straight-line graph.
(-9,5)
18
-6
(9,-1)
In your own words,
write down a definition
of the y-intercept and
If the line slopes up from left to right, then the gradient
is positive.
If the line slopes down from left to right, then the
• On boards, draw a set of axes from -5 to 5 in both the x and y directions
• In your pairs, label yourselves A and B
• Person A needs to draw a line graph on their axes without showing
person B
• Now person A describes the line graph to person B, who draws the graph
from the description
• Once done, check that the two graphs match
• If they do, sketch the graph and description given on a piece of square
paper
• If they don’t, as a pair work out what went wrong, and sketch the
correct graph with a correct description on a piece of square paper
• Repeat the process, swapping roles.
Draw two parallel lines.
What do you notice about the gradient
and y-intercept of these lines?
Is this always true?
Draw two perpendicular lines.
What do you notice about the gradient of
these lines?
Is this always true?
```