Posted by **charly** on Wednesday, April 14, 2010 at 8:34pm.

using the fact that 5pi/8=1/2(5pi/8) and the half angle identity for cos to find the exact (in terms of radicals) value of cos(5pi/8)

## Answer this Question

## Related Questions

- Calculus - Find the area in the first quadrant bounded by the arc of the circle ...
- Trig - Find the exact value of tan 5pi/12 using the half-angle identity.
- trig - find the exact value by using the appropriate half-angle identity: sin(...
- math - use exact values of the sin,cos and tan of (pi/3) and (pi/6)(which I have...
- Math - Solve (sinx-1)(cosx -1/2) = 0 where 0≤x<2pi a) pi/3, pi/2, 5pi/3...
- math - Use the exact values of the sin, cos and tan of pi/3 and pi/6, and the ...
- Math - Find the quotient of the following expression: 7(cos 5pi/6 +isin 5pi/6...
- math - Use the exact values of the sin, cos and tan of pi/3 and pi/6, and the ...
- Math - 1. On the interval [0, 2pi] what are the solutions to the equation ...
- math - use exact values of the sin,cos and tan of (pi/3) and (pi/6)(which I ...