x=2-cosθ dx=sinθdθ∫√(x-1)/(3-x)dx x积分区间[1.5,2]=∫√((1-cosθ)/1+cosθ))sinθdθ =∫((1-cosθ)/sinθ)sinθdθ=∫(1-cosθ)dθ=θ+sinθ -------x=2-cosθ x积分区间[1.5,2] ,θ积分区间为[π/3,π/2]=1+π/6-√3/2
