∫(x^2+2x-5)^(-1⼀2)dx

2025-03-11 07:04:33
推荐回答(1个)
回答1:

∫dx/√(x²+2x-5) = ∫dx/√[(x+1)²-6]
令x+1=√6*secz,dx=√6*secz*tanz dz,假设x+1>√6,0≤z<π/2
cosz=√6/(x+1),sinz=√(x²+2x-5)/(x+1)
原式= ∫(√6*secz*tanz)/√(6tan²z) dz
= ∫(secz*tanz)/tanz dz
= ∫secz dz
= ln|secz+tanz| + C
= ln|(x+1)/√6 + √(x²+2x-5)/√6| + C
= ln|x+1+√(x²+2x-5)| + C''