SOLUTION: What's the ExactValue for sin -285 degrees without using a calculator ?

Algebra ->  Trigonometry-basics -> SOLUTION: What's the ExactValue for sin -285 degrees without using a calculator ?      Log On


   



Question 577853: What's the ExactValue for sin -285 degrees without using a calculator ?
Answer by scott8148(6628) About Me  (Show Source):
You can put this solution on YOUR website!
sin(-285º) = sin(75º) = sin(45º + 30º) = [sin(45º)][cos(30º)] + [cos(45º)][sin(30º)]

sin(-285º) = {[sqrt(2)] / 2}{[sqrt(3)] / 2} + {[sqrt(2)] / 2}{1 / 2}