Question

Express each of the following in terms of a reference angle. Explain, please.

Answer 1

Sin 45 = sin 45
sin 135 = sin (180 - 45) = sin 45
sin(225) = -sin(180 + 45) = -sin 45
sin 315 = -sin(360 - 45) = -sin 45

cos 224.5 = -cos(180 + 44.5) = -cos 44.5
cos 658 = cos(658 - 360) = cos 298 = cos(360 - 62) = cos 62
cos 145.7 = -cos (180 - 34.3) = -cos 34.3
sin (-201) = sin (360 - 201) = sin(159) = sin (180 - 159) = sin 21