Question

Rewrite the sine function f(x)=2sin(x+π2)−1
as a cosine function.(1 point)

f(x)=2cos(x)−1


f(x)=2cos(x+π)−1


f(x)=2cos(x+π4)−1


f(x)=2cos(x−π2)−1

Answer 1

f(x) = 2cos(x) − 1

Reason: sin(x + π/2) = cos x, so 2 sin(x + π/2) − 1 = 2 cos x − 1.