Question

化简:

       (1)；

       (2)sin(-α-5π)·cos(α-)-tan(α-)·tan(2π-α).

      

Answer 1

解析:(1)?

       ==1.?

       (2)sin(-α-5π)·cos(α-)-tan(α-)·tan(2π-α)??

       =sin(π-α)·sinα+cotα·(-tanα)?

       =sin²α-1=-cos²α.