If sin 57=m then express the following questions

Question

1. Sin 237
2. cos 33
3. cos 3
4. cos 66

Answer 1

sin 237 = sin(180+57) = -sin 57 = -m
cos 33 = cos(90-57) = sin 57 = m

cos 3 = cos(60-57) = cos60cos57+sin60sin57 = m/2 + m√3/2 = m/2(1+√3)

cos 66 = cos(60+6)
= cos60cos6 - sin60sin6
Use your double angle formulas to get sin(6) and cos(6) from cos(3) and sin(3)