5.5 Multiple-Angle and Product-Sum Formulas

BASIC INFORMATION

In unit 5.5, we learn the double-angle formulas, the power-reducing formulas, and the half-angle formulas.  We will be given all the formulas except for the double-anglge formulas on the test.  We also need to know how to derive all the formulas for the test.

DOUBLE-ANGLE FORMULAS:

HOW TO DERIVE THE DOUBLE-ANGLE FORMULAS:

POWER-REDUCING FORMULAS:

HOW TO DERIVE THE POWER-REDUCING FORMULAS:

HALF-ANGLE FORMULAS:

HOW TO DERIVE THE HALF-ANGLE FORMULAS:

If any of these don't make sense to you, watch this video on how to derive the formulas:

Visit the sites below for additional help:

(Pink) Trig Formula Sheet From Lat Year

Help with the Double-Angle Formulas

Help with Power-Reducing Formula

Help with Half-Angle Formula

Video on How to Derive Half-Angle Formulas