Understanding angle addition formulas

The  exercise appears under the Trigonometry Math Mission. This exercise helps to encourage understanding the angle addition formulas via their proofs.

Types of Problems
There is one type of problem in this exercise:


 * 1) Move the cards, prove the formula: This problem presents a diagram and an outline of the proof of an angle addition formula. The student is expected to take the cards and place them in a correct order to justify the steps of the proof.Uaaf1.png

Strategies
Knowledge of the angle addition formulas proofs is encouraged beforehand to ensure success on this exercise.
 * 1) The sine formulas are $$ sin(x\pm y)=sin(x)cos(y)\pm cos(x)sin(y)$$.
 * 2) The cosine formulas are $$ cos(x\pm y)=cos(x)cos(y)\mp sin(x)sin(y)$$.

Real-life Applications

 * 1) Manipulation of trigonometric expressions is important for being able to prove identities and solve equations with trigonometric functions.
 * 2) Trigonometry itself has several applications in physics regarding motion.