Education Technology

Mathematics lessons for IB® Diploma Programme

Applications and Interpretation | Geometry and Trigonometry

Proof of Identities

This lesson involves discovering, visualizing and proving trigonometric identities.

Planning and Resources


  • Students will be able to interpret reciprocal, negative angle, cofunction, and Pythagorean identities in terms of the graphs of the trigonometric functions involved.
  • Students will be able to prove trigonometric identities algebraically.
  • Students will be able to visualize trigonometric identities graphically.


  • Cofunction Identities
  • Identity
  • Negative Angle Identities
  • Pythagorean Identities
  • Reciprocal Identities
  • Trigonometric Identities