Included in this zip folder are 4 PDF files. 1 is the proof, 1 is an assignment and 2 are student 1 page printables. A brief description of each:
The proof is a 32 page file. The identity cos(A-B)=cosAcosB+sinAsinB is proved. The distance formula is used to derive this identity based on a rotated angle in the unit circle. The student must previously know:
1. The definition of sine
2. The definition of cosine
3. The Pythagorean Identities
4. Expand a binomial
The 1st 11 slides are free in the preview section.
Printable #1 is 1 page. This is for the proof. The appropriate pictures are included for the student to follow along and formulate the proof.
Printable #2 is a 1 page reference of trig identities. The following identities are on the reference:
1. Odd/Even Identities
2. Cofunction Identities
3. Sum and Difference Identities
4. Half Angle Identities
5. Pythagorean Identities
6. Double Angle Identities
Assignment #1 is a 15 question multiple choice assignment. The student must recognize the sum and difference identities for sine, cosine and tangent. It is on 1 page for easy printing. If you desire, it can be used at socrative.com and the socrative share number is included in the file.
Thank you for looking