设cos(π/4+x)=3/5,x∈(3π/4,7π/4),求(sin2x+2sin²x)/(1-tanx)

问题描述:

设cos(π/4+x)=3/5,x∈(3π/4,7π/4),求(sin2x+2sin²x)/(1-tanx)

3π/4