Question

积分题第二道设根号(x+1)=他x=t^2 -1 dx=2tdt这步咋算的

Answer 1

∫(t^2-1)×t/2t dt

= 1/2 ∫(t^2)dt - 1/2 ∫dt

= 1/6 t^3 - 1/2 t + C