Sine Difference Formula and Cosine Addition Formula

This applet shows a proof of the difference formula for sine,  and a proof of the addition formula for cosine,  using the formula .

This is a Java Applet created using GeoGebra from www.geogebra.org - it looks like you don't have Java installed, please go to www.java.com

Reference:

Proof of the Difference Formula for Sine and of the Addition Formula for Cosine" from the Wolfram Demonstrations Project
 http://demonstrations.wolfram.com/ProofOfTheDifferenceFormulaForSineAndOfTheAdditionFormulaFor/

Contributed by: Izidor Hafner