题目内容：

cosθ=-3/5,角θ在（π/2,π）求2/cos（π/2-θ）+2cos（π-θ）sin(13/6π)/sinθ的值,
cosθ=-3/5,角θ在（π/2,π）求2/cos（π/2-θ）+2cos（π-θ）sin(13/6π)/sinθ的值