cos(π/11)cos(2π/11)cos(3π/11)cos(4π/11)cos(5π/11)
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cos(π/11)cos(2π/11)cos(3π/11)cos(4π/11)cos(5π/11)
cos(π/11)cos(2π/11)cos(3π/11)cos(4π/11)cos(5π/11)
cos(π/11)cos(2π/11)cos(3π/11)cos(4π/11)cos(5π/11)
cos(π/11)cos(2π/11)cos(3π/11)cos(4π/11)cos(5π/11)
=2sin(π/11)cos(π/11)cos(2π/11)cos(3π/11)cos(4π/11)cos(5π/11)/[2sin(π/11)]
=2sin(2π/11)cos(2π/11)cos(3π/11)cos(4π/11)cos(5π/11)/[4sin(π/11)]
=2sin(4π/11)cos(4π/11)cos(3π/11)cos(5π/11)/[8sin(π/11)]
=sin(8π/11)cos(3π/11)cos(5π/11)/[8sin(π/11)]
=2sin(3π/11)cos(3π/11)cos(5π/11)/[16sin(π/11)]
=sin(6π/11)cos(5π/11)/[16sin(π/11)]
=2sin(5π/11)cos(5π/11)/[32sin(π/11)]
=sin(10π/11)/[32sin(π/11)]
=sin(1π/11)/[32sin(π/11)]
=1/32
求值:cos(π/11)cos(2π/11)cos(3π/11)cos(4π/11)cos(5π/11)
求值:cos(π/11)-cos(2π/11)+cos(3π/11)-cos(4π/11)+cos(5π/11)
cos(π/11)cos(2π/11)cos(3π/11)cos(4π/11)cos(5π/11)
cos(π/11)cos(2π/11)cos(3π/11)cos(4π/11)cos(5π/11)怎么解
求cos(π/11)cos(2π/11)cos(3π/11)cos(4π/11)cos(5π/11)求值:cos(π/11)cos(2π/11)cos(3π/11)cos(4π/11)cos(5π/11)(5/24)(11/24)=5/11?,而且过程和题好像都没关系。
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