Question

im taking test
need answer quick'
use the sum and difference identities to write the expression as the cosine of the angle. be sure to simplify the anglee:

cospi/9cospi/3-sin
pi/9sinpi/3

Answer 1

You're taking a test? Do you want us to help you cheat??

My, goodness, no!!

Answer 2

hint:
cos(A+B) = cosAcosB - sinAsinB