cos(π/4+a)=3/5,π/2≤a<3π/2,求(1-cos2a+sin2a)/1-tana的值?

问题描述:

cos(π/4+a)=3/5,π/2≤a<3π/2,求(1-cos2a+sin2a)/1-tana的值?


∵ π/2≤a