Lesson Plan: Double-Angle and Half-Angle Identities Mathematics • Second Year of Secondary School
This lesson plan includes the objectives, prerequisites, and exclusions of the lesson teaching students how to use the double-angle and half-angle identities to evaluate trigonometric values.
Objectives
Students will be able to
- derive and recall the double- and half-angle identities for sine, cosine, and tangent from the sum and difference formulas:
- use the identities along with the Pythagorean identities to simplify expressions,
- use the identities to evaluate expressions, including determining the exact values of trigonometric functions, for example, .
Prerequisites
Students should already be familiar with
- radians,
- the Pythagorean identities,
- the sum and difference formulas for sine, cosine, and tangent.
Exclusions
Students will not cover
- solving equations.
