您的位置: 首页  >  作业答案  >  其他  >  1.已知8cos(2x+y)+5cosy=0,求tan(x+y)*tanx的值.2.已知关于x的方程x^2+px+q=0的两根是tanx,tany,求sin(x+y)/cos(x-y)的值.3.化简:sin(x-y)/(sinx*siny)+sin(y-z)/(siny*sinz)+sin(z-x)/(sinz*sinx).

1.已知8cos(2x+y)+5cosy=0,求tan(x+y)*tanx的值.2.已知关于x的方程x^2+px+q=0的两根是tanx,tany,求sin(x+y)/cos(x-y)的值.3.化简:sin(x-y)/(sinx*siny)+sin(y-z)/(siny*sinz)+sin(z-x)/(sinz*sinx).

分类: 作业答案 • 2022-06-21 19:39:32
问题描述：

1.已知8cos(2x+y)+5cosy=0,求tan(x+y)*tanx的值.
2.已知关于x的方程x^2+px+q=0的两根是tanx,tany,求sin(x+y)/cos(x-y)的值.
3.化简:sin(x-y)/(sinx*siny)+sin(y-z)/(siny*sinz)+sin(z-x)/(sinz*sinx).

答

3:通分,将3个分式的分母化成相同的,即sin(x-y)sinz/(sinxsinysinz) +sin(y-z)sinx/(sinxsinysinz) +sin(z-x)siny/(sinxsinysinz)再将分子展开,即sinxcosysinz-cosxsinysinz+sinycoszsinx-cosysinzsinx+sinzcosxsiny-...

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