Evaluate the expression:
1) 1 - 2sin^2 π/2
Recall your double-angle formula
cos 2x = 1 - 2sin^2 x
So this is just cos(2 * π/2) = cos π = -1
or, since sin π/2 = 1, 1 - 2*1 = -1
1) 1 - 2sin^2 π/2
cos 2x = 1 - 2sin^2 x
So this is just cos(2 * π/2) = cos π = -1
or, since sin π/2 = 1, 1 - 2*1 = -1