解析因为[根(x^2+1)-x][根(x^2+1)+x]=1则[根(x^2+1)-x]=1/[根(x^2+1)+x]即[-x+根(x^2+1)]=1/[根(x^2+1)+x]即ln[-x+根(x^2+1)]=ln1/[根(x^2+1)+x]
