Given the function f (x) = (SiNx cosx) SiNx, X belongs to R 1. Change it into the form of asin (Wx + a) + B. 2. Find the period

Given the function f (x) = (SiNx cosx) SiNx, X belongs to R 1. Change it into the form of asin (Wx + a) + B. 2. Find the period

1.f(x)=(sinx-cosx)sinx
=sin^2x-cosxsinx
=(1-cos2x)/2-1/2*sin2x
=-1/2(sin2x+cos2x)+1/2
=-√2/2sin(2x+π/4)+1/2
2. The minimum positive period T = 2 π / 2 = π

The following four functions are given: 1) y = SiNx + cosx; 2) y = SiNx cosx; 3) y = SiNx · cosx; 4) y = sinxcosx. The function with neither maximum nor minimum on (0, π 2) is______ (write the serial number of all correct conclusions)

① Y = SiNx + cosx = 2Sin (x + π 4), X ∈ (0, π 2), x + π 4 ∈ & nbsp; (π 4, 3 π 4), y ∈ (22, 1], with maximum 1; ② y = SiNx cosx = 2Sin (x + π 4), X − π 4 ∈ & nbsp; (− π 4, π 4), y ∈ (− 22, 22), without maximum and minimum; ③ y = SiNx · cosx = 12sin2x ∈ (...)