求证[tan(2π-α)sin(-2π-α)cos(6π-α)]/[sin(α+3π/2)cos(α+3π/2)]=-tanα

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求证[tan(2π-α)sin(-2π-α)cos(6π-α)]/[sin(α+3π/2)cos(α+3π/2)]=-tanα

求证[tan(2π-α)sin(-2π-α)cos(6π-α)]/[sin(α+3π/2)cos(α+3π/2)]=-tanα
求证[tan(2π-α)sin(-2π-α)cos(6π-α)]/[sin(α+3π/2)cos(α+3π/2)]=-tanα

求证[tan(2π-α)sin(-2π-α)cos(6π-α)]/[sin(α+3π/2)cos(α+3π/2)]=-tanα
这都是诱导公式
tan(2π-α)=tan(-α)=-tanα
sin(-2π-α)=sin(-α)=-sinα
cos(6π-α)=cos(-α)=cosα
sin(α+3π/2)=-cosα
cos(α+3π/2)=sinα
所以原式=(-tanα)(-sinα)cosα/[(-cosα)sinα]=-tanα