Question

(1/2)cos二分三圆周率-tan三分之二圆周率-sin三分之圆周率+cos四分之十七圆周率sin（负四分之十七圆周.

Answer 1

cos(3π/2)-tan(2π/3)-sin(π/3)+cos(17π/4)sin(-17π/4)=cos(π/2)-(-√3)-(√3/2)-cos(π/4)sin(π/4)=0+√3/2-(√2/2)(√2/2)=(√3-1)/2