Transformations of Trigonometric Functions (Edexcel IAL Maths)

Spec point — 1.12

Transformations of trigonometric functions

What are transformations of trigonometric functions?

• You should already have a good idea about translating, stretching and reflecting basic functions (see Transformations of Functions)

• The basic principles are exactly the same for transforming any trigonometric graph

  • y = n cos x gives a vertical stretch or squash
  • y = sin nx gives a horizontal stretch or squash
  • y = tan (x + c) gives a horizontal translation

Exam Hint

• Always sketch with a pencil and draw a smooth curve.
• When you sketch the transformation of a graph, be sure to indicate the new coordinates of any points that are marked on the original graph.
• Try to indicate the coordinates of points where the new graph intersects the axes.

Worked Example