# trig

posted by
**Blake** on
.

A coil of wire rotating in a magnetic field induces a coltage E=20sin((PIa/4) - (PI/2)). Use an identity to express this in terms of cos(PIa/4).

Types of Identities:

Double Angle, Half Angle, Sum and Difference of Sine, Cosine, and Tangent, Pythagorean, Reciprocal, Quotient.

Thanks