Use an identity to write each expression as a trig function value or as a single number.
1-2sin^2(22 1/2 degrees)
and
1/4 - 1/2 sin^2 (47.1 degrees)
Thanks for reading!
Hello Thatoneguy12345These both use the identity $\displaystyle \cos2\theta =1-2\sin^2\theta$
1) $\displaystyle 1-2\sin^222\tfrac12^o=\cos 45^o=\frac{1}{\sqrt2}$
2) $\displaystyle \tfrac14-\tfrac12\sin^247.1^o=\tfrac14(1-2\sin^247.1^o)=\tfrac14\cos 94.2^o$, and you can't simplify this any further.
Grandad