The Pythagorean identity Whiteboard exercise Play

The Pythagorean identity revisited Student activity Play

The square of a difference Animation Play

The steepest part of a road Animation Play

The sum and difference of functions Whiteboard exercise Play

The sum and difference of functions Student activity Play

The sum and difference of trigonometric functions Whiteboard exercise Play

The sum and the difference of irrational numbers Whiteboard exercise Play

The tangent and cotangent functions revisited Student activity Play

The tangent and the cotangent are inversely proportional Student activity Play

The tangent and the secant Animation Play

The tangent and the secant Student activity Play

The two square tables Whiteboard exercise Play

Tickets Animation Play

Total energy Student activity Play

Trigonometric functions of the sum and difference of angles (1) Whiteboard presentation Play

Trigonometric functions of the sum and difference of angles (1) Class activity Play

Trigonometric functions of the sum and difference of angles (2) Class activity Play

Trigonometric functions of the sum and difference of angles (2) Whiteboard presentation Play

Trigonometric identities – investigations Simulation Play

Trigonometric identities – investigations Student activity Play

Trigonometric identity for tangent and cotangent Simulation Play

Updating a spreadsheet Whiteboard exercise Play

Updating a spreadsheet Student activity Play

Using the difference identity for the tangent Whiteboard exercise Play