Question

cos(Sin^(-1)1/2) Without calculator..

Answer 1

\[\cos (\sin^{-1} 1/2)\]

Answer 2

hit:
\[\sin 30 = \frac 12\]
\[\sin 60 = \frac {\sqrt 3}{2}\]
\[\sin 45 = \frac{\sqrt 2}{2}\]
\[\sin 0 = 0\]
\[\sin 90 = 1\]
so what do you think is \[\sin^{-1} (1/2)\]