简单分析一下即可，详情如图所示
x＝－1/2×(1－2x)＋1/2,所以 ∫xdx/√(5+x-x^2) ＝－1/2×∫(1-2x)dx/√(5+x-x^2)＋1/2×∫dx/√(5+x-x^2) ＝－1/2×∫1/√(5+x-x^2) d(5+x-x^2) ＋ 1/2×∫1/√[21/4－(x-1/2)^2] ＝－√(5+x-x^2)＋1/2×arcsin[(2x-1)/√(21)]＋C
