Question

use a half-angle formula to find the exact value of each expression
sin15

Answer 1

\[
\sin^2(\frac a2) = \frac 12\{1 - \cos(a)\}
\]

Answer 2

Set a = 30 degrees in the above half-angle formula and compute sin(15).

Answer 3

cos 30 \[\frac{ \sqrt{3} }{ 2}\]

Answer 4

correct. \[
\sin^2(15) = \frac 12\{1 - \frac{\sqrt 3}{2}\} = \frac 14\{2-\sqrt {3}\} \\
\sin(15) = \frac 12\sqrt{2- \sqrt{3}}
\]

Answer 5

im confused can i show you my work?

Answer 6

Go ahead.