化简 [Sin(π+α)\tan(π+α)] ×[ cot(2π-α)\cos(π+α)]×[sec(2π-α)\csc

[Sin(π+α)\tan(π+α)] ×[ cot(2π-α)\cos(π+α)]×[sec(2π-α)\csc(π-α)]
= [(-sinα)\tanα] ×[(-cotα)\(-cosα)]×[secα\cscα]
= [(-sinα)×cosα\sinα] ×[(cosα\sinα)\cosα)]×(sinα\cosα)
=-cosα×(1\sinα)×(sinα\cosα)
=-1