cos(-83/6派)= 填空题

cos(-83/6派)= 填空题
cos(-83/6派)= 填空题

cos(-83/6派)= 填空题
因为：-83π/6 = -13π-5π/6
所以：cos(-83π/6)=cos(-13π-5π/6)=cos(-12π-π-5π/6)
=cos(-π-5π/6)=-cos(π+5π/6)=cos(5π/6)=cos(π-π/6)
=-cos(π/6)
= -1/2

二分之根三，把它化简就可以了 因为：-83π/6 = -13π-5π/6 所以：cos(-83π/6)=cos(-13π-5π/6)=cos(-12π-π-5π/6) =cos(-π-5π/6)=-cos(π+5π/6)=cos(5π/6)=cos(π-π/6) =-cos(π/6) = -1/2cos(-12π-π-5π/6)...

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二分之根三，把它化简就可以了

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