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MA15-08 Maths Coming soon

Equations of Perpendicular Lines

MA15-08

This lesson is coming soon.

In this lesson

Use the negative-reciprocal gradient rule to find the equation of a line perpendicular to a given line, then find where that new line crosses the axes correctly.

What it covers

  • The negative-reciprocal rule: flip the fraction, then change its sign
  • Finding the equation of a line perpendicular to a given line, through a stated point
  • Finding where a line crosses the axes: set y = 0 for the x-axis, set x = 0 for the y-axis

Key words

For: AQA GCSE 8300, Edexcel GCSE 1MA1, Eduqas GCSE C300, OCR GCSE J560, Edexcel IGCSE 4MA1, Cambridge IGCSE 0580

On the specification

BoardSpecStatement
AQA GCSE 8300A9Plot graphs of equations that correspond to straight-line graphs in the coordinate plane
Edexcel GCSE 1MA1A9Plot graphs of equations that correspond to straight-line graphs in the coordinate plane; use the form y = mx + c to identify parallel lines; find the equation of the line through two given points or through one point with a given gradient
Eduqas GCSE C300HA9Plot graphs of equations that correspond to straight-line graphs in the coordinate plane; use the form y = mx + c to identify parallel and perpendicular lines; find the equation of the line through two given points, or through one point with a given gradient
OCR GCSE J5607.02bIdentify and find equations of parallel lines.
Edexcel IGCSE 4MA1H3.3GFind the equation of a straight line parallel to a given line; find the equation of a straight line perpendicular to a given line
Cambridge IGCSE 0580C3.7Extended content only.
Cambridge IGCSE 0580E3.7Find the gradient and equation of a straight line perpendicular to a given line.
For teachers

This GCSE Maths lesson teaches equations of perpendicular lines. By the end, students should be able to use the negative-reciprocal gradient rule to find the equation of a line perpendicular to a given line, then find where that new line crosses the axes correctly. It works through two worked examples and the mistakes examiners report.