Rewrite the expression in terms of the first power of the cosine. Use a graphing utility to graph both expressions to verify that both forms are the same.

Question

4 sin²(x/2)

= ___________

Answer 1

4sin²(x/2) = 4(1 - cosx)/2 = 2 - 2cosx

Answer 2

4 sin² (x/2)

4 [(±√(1 - cos x)) / 2]²

4 (1 - cos x) / 4

1 - cos x