6.2: Right angle trigonometry January 6, 2009

Objectives Learn basic concepts about trigonometric functions Apply right triangle trigonometry Understand complementary angles and cofunctions.

Basics of Trigonometry Functions sin θ = O/H cos θ = A/H tan θ = O/A csc θ = H/O sec θ = H/A cot θ = A/O

Solving a triangle Remember the Pythagorean theorem? If a= 5 and c= 10, what is b?

Finding missing angles c=17, a=8 What is sin θ? ..cos θ? …tan θ?

Finding missing sides c=10, β=60° How long is b?

Complementary angles and cofunctions A and B are complementary. sin A= cos A= tan A= cot A= sec A= csc A=

Trig functions of a 45-45-90 triangle Sin 45 Csc 45 Cos 45 Sec 45 Tan 45 Cot 45

Trig functions of a 30-60-90 triangle θ Sin θ Cos θ Tan θ Csc θ Sec θ Cot θ 30° 60°

Assignment 17-28 33-38 49-52