Question

第2题，要计算过程，，，谢谢

Answer 1

(1)
cos(-17π/4)
=cos(-4π -π/4)
=cos(-π/4)
=cos(π/4)
=√2/2
(2)
sin(-1574°)
=sin(-4×360°-134°)
=sin(-134°)
=-sin134°
=-sin(180°-134°)
=-sin46°
(3)
sin(-2160°52')
=sin(-2160°-52')
=sin(-6×360°-52')
=sin(-52')
=-sin52'
(4)
cos(-1751°36')
=cos(5×360°-1751°36')
=cos(48°24')
=cos48.4°
(5)
cos1615°8'
=cos(4×360°+175°8')
=cos(175°8')
=-cos(180°-175°8')
=-cos4°52'
(6)
sin(-26π/3)
=sin(-8π-2π/3)
=sin(-2π/3)
=-sin(2π/3)
=-sin(π-2π/3)
=-sin(π/3)
=-√3/2