为什么sin11π/3=sin(4π-π/3)=-sinπ/3=-根号3/2,sin(4π-π/3)=-sinπ/3我不
1个回答
sin11π/3=sin(4π-π/3)
=sin(-π/3+2*2π)
2*2π即2π的整数倍
所以可以去掉
=sin(-π/3)
=-sinπ/3
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