求 ∫dx/(x^2-2x-3) 在(-1,3)区间内的积分

∫[-1,3] dx/(x²-2x-3)= ∫[-1,3] dx/[(x-3)(x+1)]= (1/4)∫[-1,3] [1/(x-3) - 1/(x+1)] dx= (1/4)ln|(x-3)/(x+1)|= (1/4)ln(0/4) - (1/4)ln(-4/0)= ∞这个积分发散