f(0)=3sin(w0+π/6),=3sin(π/6)=3/2,π/2为最小正周期 ∴根据公式T=2π/w ∴W=4∴f(x)=3sin(4x+π/6)第三问f(a/4+π/12)=9/5∴f(a/4+π/12)=3sin(4(a/4+π/12)+π/6)=3sin(a+π/3+π/6)=3cos(a)=9/5所以cosa=3/5根...