cos1/2,娜可露露晚莹cos

tan(π/4 a)=1/2 求(sin2a-cos平方a)÷(1 cos2a)
cos2x=2cos²x-1所以y=(1 cos2x)/2所以t=2π/2
y=2cos1/2x \ y=2cos(x-π/2) \ y=cos(1/2x π/4
根号{1/2 [1/2*根号(1 cos2a)/2]},a∈(3π/2,2π)
2,3π/4,13π/12,7π/4 (2)|f(x)-m| f(x)=sin(2x θ) √3cos(2x θ)=