The fourth in a series of powerpoint shows on trigonometry. It consist of 2 powerpoints the first of which focus on compound and double angles. I prove the double and compound angle identities and then used them to prove other identities. In the second powerpoint I make use of the compound and double angles to solve equations.
Each slide is animated in a way that make it very easy to explain as you go on.
As a bonus I included an investigation on discovering the compound angles.
**Please Note that in South Africa we use degree when doing Trigonometry, not Radians.