Question

When taking the sine and cosine of different angles in your calculator, why are they sometimes the same? Why do they sometimes produce the same answer? ex: sin 55* = 0.819152044 and cos35* = 0.819152044 or sine 30* and cos 60*

Answer 1

sin(theta) = 90 - cos(theta)

cos(theta) = 90 - sin(theta)