AI generatedAlgebraGCSE Higher

Finding an equation of a perpendicular line

Use the perpendicular gradient and a given point.

  • For a non-vertical straight line, use .
  • The gradient is change in divided by change in . The intercept is the value when .
  • Substitute a known point to find missing constant. Show the same operation on both sides.

Example 1

Find the equation of the line through perpendicular to .

Use the negative reciprocal of the given gradient.Substitute the point into .Subtract the numerical term from both sides.Substitute and into .

Example 2

Find the equation of the line through perpendicular to .

Use the negative reciprocal of the given gradient.Substitute the point into .Subtract the numerical term from both sides.Substitute and into .

Your turn

Question 1

Find the equation of the line through perpendicular to .

Check answer
Use the negative reciprocal of the given gradient.Substitute the point into .Subtract the numerical term from both sides.Substitute and into .
Question 2

Find the equation of the line through perpendicular to .

Check answer
Use the negative reciprocal of the given gradient.Substitute the point into .Subtract the numerical term from both sides.Substitute and into .
Question 3

Find the equation of the line through perpendicular to .

Check answer
Use the negative reciprocal of the given gradient.Substitute the point into .Subtract the numerical term from both sides.Substitute and into .
Question 4

Find the equation of the line through perpendicular to .

Check answer
Use the negative reciprocal of the given gradient.Substitute the point into .Subtract the numerical term from both sides.Substitute and into .
Question 5

Find the equation of the line through perpendicular to .

Check answer
Use the negative reciprocal of the given gradient.Substitute the point into .Subtract the numerical term from both sides.Substitute and into .
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