求值 sin9派/2+cos(-17派/3)+tan5派/4

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求值 sin9派/2+cos(-17派/3)+tan5派/4

求值 sin9派/2+cos(-17派/3)+tan5派/4
求值 sin9派/2+cos(-17派/3)+tan5派/4

求值 sin9派/2+cos(-17派/3)+tan5派/4
sin(9π/2)+cos(-17π/3)+tan(5π/4)
=sin(π/2+4π)+cos(17π/3)+tan(π+π/4)
=sin(π/2)+cos(-π/3+6π)+tan(π/4)
=1+cosπ/3+1
=2+1/2=3/2

=sin(4π+π/2)+cos(-6π+π/3)+tan(π+π/4)
=sinπ/2+cosπ/3-tanπ/4
=1+1/2-1
=1/2