θ∈(-π/2,0),则直线xcosθ+ysinθ+1=0的倾斜角为
问题描述:
θ∈(-π/2,0),则直线xcosθ+ysinθ+1=0的倾斜角为
A.-θ B.π/2+θ C.π+θ D.π/2-θ
答
k=-cosθ/sinθ=-cotθ
tant=cot(π/2+θ)
答案为B