Two lines are perpendicular if they meet at right angles.

An irrational number is one that cannot be written in the form a/b where a and b are integers and b is not equal to 0

A surd is an irrational number expressed as the root of a rational number.

Identifying perpendicular linear graphs

Maths

The work on gradient in this unit is expanded further in the future unit by considering gradient as the rate of change and interpreting this in context. The gradient of the tangent is introduced as a way of estimating the gradient of a curve.

In the prior unit, pupils drew a linear graph from its equation and related the features of the graph to its equation. In this unit, pupils consider equations that produce parallel or perpendicular graphs and how their equations relate to each other.

Linear graphs

Match each number to its negative reciprocal.

Select the equation of a line perpendicular to the line with equation $$ y = {1\over 2}x$$.

Which of these are equations of a line perpendicular to the line with equation $$ 3y = 2x + 6$$?

Which of these are equations for lines which are perpendicular to the line with equation $$y + 2.5x = 0$$?

Which is the equation of the line which passes through the point (3, -1) and is perpendicular to the line with equation $$y =2-{1\over 3}x$$?

Which of these are equations for lines which are perpendicular to the line with equation $$y = {1\over\sqrt{20}}x$$?

Which of these show two lines which are perpendicular? 

Which of these values is the reciprocal of 4?

Which of these coordinates lie on the line $$x = 4.5$$?

Which of these lines are parallel to the line with equation $$2y-x = 5$$?

A line has gradient 4 and passes through the coordinate (3, 9). What is the equation of the line? 

Starter Quiz