# Lesson Plan: Simplifying Trigonometric Expressions Using Trigonometric Identities Mathematics • 10th Grade

This lesson plan includes the objectives, prerequisites, and exclusions of the lesson teaching students how to simplify trigonometric expressions by applying trigonometric identities.

#### Objectives

Students will be able to

• identify whether an equation represents an identity,
• recall and use the Pythagorean identities to simplify expressions,
• use combinations of trigonometric identities, including cofunction identities, shift identities, and Pythagorean identities, to simplify expressions, including reciprocal trigonometric functions,
• use the trigonometric identities to simplify rational trigonometric expressions.

#### Prerequisites

Students should already be familiar with

• basic trigonometric identities including the definitions of the tangent function and reciprocal trigonometric functions,
• complementary function identities and shift identities.

#### Exclusions

Students will not cover

• the sum and difference formulas,
• the double- and half-angle formulas.