Proofs of the sum and difference identities.

1. Sum and Difference
Proofs (continued ...)
cosbmw by marymactavish

2. A Quiz
PICT0015 by matt-hieu ergosteur

9. Proofs of the Sum and Difference Identities ...
Rotate ROP so that
O
O OP lies on the
positive x-axis
TO BE COMPLETED

10. Proofs of the Sum and Difference Identities ...
Rotate ROP so
O
O that OP lies on the
positive x-axis

11. Recall the Even and Odd Identities
The sine and tangent functions are ODD functions.
Cosine is an EVEN function.
sin(-x) = -sin(x) cos(-x) = cos(x) tan(-x) = -tan(x)

12. Proofs of the Sum and Difference Identities ...
Rotate ∠ROP so that OP
O
O lies on the positive x-axis

13. Recall the Even and Odd Identities
The sine and tangent functions are ODD functions.
Cosine is an EVEN function.
sin(-x) = -sin(x) cos(-x) = cos(x) tan(-x) = -tan(x)