Use a doubleangle formula to find the exact value of the giv

Use a double-angle formula to find the exact value of the given expression. 1 minus 2 sin^2 22.5Degree 1 minus 2 sin^222.5Degree = (Simplify your answer, including any radicals. Use integers or fractions for any numbers in the expression.)

Solution

1-2sin²A=cos2A

1-2sin²22.5⁰

=cos(2*22.5⁰)

=cos45⁰

=1/2

=(2)/2