请问 ２log secα cos(2π-α)的值是多少?

请问 ２log secα cos(2π-α)的值是多少?
请问 ２log secα cos(2π-α)的值是多少?

请问 ２log secα cos(2π-α)的值是多少?
2log secα cos(2π-α)
=2log secα cosα ------------------------------cos(2π-α) = cosα
=2log1 ------------------------------正割和余弦互为倒数
=0 ------------------------------log1 = 0