求值(1)sin29/6π(2)cos31/4π(3)tan(-1560°)

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求值(1)sin29/6π(2)cos31/4π(3)tan(-1560°)求值(1)sin29/6π(2)cos31/4π(3)tan(-1560°)求值(1)sin29/6π(2)cos31/4π

求值(1)sin29/6π(2)cos31/4π(3)tan(-1560°)
求值(1)sin29/6π(2)cos31/4π(3)tan(-1560°)

求值(1)sin29/6π(2)cos31/4π(3)tan(-1560°)

sin(29/6π)
=sin(4π+5π/6)
=sin(5π/6)
=sin(π-π/6)
=sin(π/6)
=1/2
cos(31/4π)
=cos(8π-π/4)
=cos(-π/4)
=cosπ/4
=√2/2
tan(-1560)
=-tan(1560)
=-tan(180×9-60)
=-tan(-60)
=tan(60)
=√3

(1)相当于sin5/6=0.5(2)相当于cos7/4=二分之根号二(3)相当于tan240=根号3