# Mathematics

posted by
**Edwards**
.

1. Show that Sin3 Theta - Cos2 Theta = (1 - Sin Theta)(4Sin^2 Theta + 2Sin Theta - 1).

Without using a calculator, show that Theta = 18 degrees is an exact solution of the equation Sin3 Theta = Cos2 Theta.

Justifying your answer, find the exact values of:

i) Sin18 degrees.

ii) Sin234 degrees.