计算(1)sin420度*cos750度+sin(-330度)*cos(-660度) tan675度+tan765度-tan(-330度)+tan(-690度(3)sin25TT/6+cos25TT/3+tan(-25TT/4)要过程
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![计算(1)sin420度*cos750度+sin(-330度)*cos(-660度) tan675度+tan765度-tan(-330度)+tan(-690度(3)sin25TT/6+cos25TT/3+tan(-25TT/4)要过程](/uploads/image/z/964943-71-3.jpg?t=%E8%AE%A1%E7%AE%97%EF%BC%881%EF%BC%89sin420%E5%BA%A6%2Acos750%E5%BA%A6%2Bsin%EF%BC%88-330%E5%BA%A6%EF%BC%89%2Acos%EF%BC%88-660%E5%BA%A6%EF%BC%89+tan675%E5%BA%A6%2Btan765%E5%BA%A6-tan%EF%BC%88-330%E5%BA%A6%EF%BC%89%2Btan%EF%BC%88-690%E5%BA%A6%EF%BC%883%EF%BC%89sin25TT%2F6%2Bcos25TT%2F3%2Btan%EF%BC%88-25TT%2F4%EF%BC%89%E8%A6%81%E8%BF%87%E7%A8%8B)
计算(1)sin420度*cos750度+sin(-330度)*cos(-660度) tan675度+tan765度-tan(-330度)+tan(-690度(3)sin25TT/6+cos25TT/3+tan(-25TT/4)要过程
计算(1)sin420度*cos750度+sin(-330度)*cos(-660度) tan675度+tan765度-tan(-330度)+tan(-690度
(3)sin25TT/6+cos25TT/3+tan(-25TT/4)要过程
计算(1)sin420度*cos750度+sin(-330度)*cos(-660度) tan675度+tan765度-tan(-330度)+tan(-690度(3)sin25TT/6+cos25TT/3+tan(-25TT/4)要过程
解(1):原式=sin(360°+60°)×cos(2×360°+30°)-sin330°×cos660°
=sin60°×cos30°-sin(360°-30°)×cos(3×360°-60°)
=sin60°×cos30°-(-sin30°)×cos(-60°)
=sin60°×cos30°+sin30°×cos60°
=√3/2×√3/2+1/2×1/2
=3/4+1/4
=1
解(2):原式=tan(2×360°-45°)+tan(2×360°+45°)+tan330°-tan690°
=-tan45°+tan45°+tan(360°-30°)-tan(2×360°-30°)
=-tan30°-(-tan30°)
=-tan30°+tan30°
=0
解3:原式=sin[4π+(π/6)]+cos[8π+(π/3)]+tan[-6π+(-π/4)]
=sin(π/6)+cos(π/3)+tan(-π/4)
=sin(π/6)+cos(π/3)-tan(π/4)
=1/2+1/2-1
=0