Posted by **joy** on Monday, December 27, 2010 at 4:20pm.

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

- precal -
**Ms. Sue**, Monday, December 27, 2010 at 4:22pm
You're taking a test? Do you want us to help you cheat??

My, goodness, no!!

- precal -
**Reiny**, Monday, December 27, 2010 at 8:51pm
hint:

cos(A+B) = cosAcosB - sinAsinB

## Answer this Question

## Related Questions

- Math - use the sum and difference identities to find the cosine angle cos pi/9 ...
- MATH - 1.)Find the exact solution algebriacally, if possible: (PLEASE SHOW ALL ...
- tRiG/ AlGeBrA - 1) Use double-angle identities to write the following expression...
- Math(Please help) - 2) Use the sum and difference identites sin[x + pi/4] + sin[...
- trig - 1) Use double-angle identities to write the following expression, using ...
- trig - A coil of wire rotating in a magnetic field induces a coltage E=20sin((...
- sine and cosine - Simplify and write the trigonometric expression in terms of ...
- trigonometric functions - im compeletely lost with the trigonometric functions...
- Math(Please help) - 1)tan Q = -3/4 Find cosQ -3^2 + 4^2 = x^2 9+16 = sqrt 25 = 5...
- Math - Use the cofunction identities to write an expression that is equivalent ...

More Related Questions