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问题: 高一数学题!~急

化简:1.cos(α-π)tan(α-2π)tan(2π-α)/sin(π+α)
2.sin的平方(-α)-tan(360度-α)tan(-α)-sin(180度-α)cos(360度-α)tan(180度+α)

解答:

(1)cos(α-π)tan(α-2π)tan(2π-α)/sin(π+α)
=-cosα*tanα*(-tanα)/-sinα
=cosα*(sinα/cosα)*tanα/-sinα
=-tanα
(2)[sin(-α)]^2-tan(2π-α)tan(-α)-sin(π-α)cos(2π-α)tan(π+α)
=[sin(-α)]^2-tan(-α)tan(-α)-sinα*cosα*tanα
=(sinα)^2-(tanα)^2-sinα*cosα*sinα/cosα
=(sinα)^2-(tanα)^2-(sinα)^2
=-(tanα)^2