SOLUTION: Use half-angle formulas to find the exact values. (a) cos 67°30' (b) sin 75° (c) tan 3π/8

Algebra ->  Trigonometry-basics -> SOLUTION: Use half-angle formulas to find the exact values. (a) cos 67°30' (b) sin 75° (c) tan 3π/8       Log On


   

Question 926994: Use half-angle formulas to find the exact values.
(a) cos 67°30'

(b) sin 75°

(c) tan 3π/8

Answer by lwsshak3(11628) About Me  (Show Source):
You can put this solution on YOUR website!
Use half-angle formulas to find the exact values.
(a) cos 67°30'=67.5˚
cos%28x%2F2%29=sqrt%28%281%2Bcosx%29%2F2%29

..
sin%28x%2F2%29=sqrt%28%281-cosx%29%2F2%29
(b) sin 75°

..
tan%28x%2F2%29=sinx%2F%281%2Bcosx%29
(c) tan+%283pi%2F8%29