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)