SOLUTION: Evaluate sin 390 degrees + cos (-45 degrees)-sin(-225 degrees)

Algebra ->  Trigonometry-basics -> SOLUTION: Evaluate sin 390 degrees + cos (-45 degrees)-sin(-225 degrees)      Log On


   

Question 180127: Evaluate sin 390 degrees + cos (-45 degrees)-sin(-225 degrees)
Answer by Mathtut(3670) About Me  (Show Source):
You can put this solution on YOUR website!
sin 390 or sin 30 degrees is 1/2
cos -45 or cos 45 degrees is sqrt%282%29%2F2
sin -225 or sin 45 degrees is sqrt%282%29%2F2
:
so 1/2+ sqrt%282%29%2F2-sqrt%282%29%2F2
:
=1/2