原式=∫(x+1-2)/(x^2+2x+3) dx
=∫(x+1)dx/(x^2+2x+3)-∫2dx/[(x+1)^2+2]
=1/2*∫d(x^2+2x+3)/(x^2+2x+3)-2∫d(x+1)/[(x+1)^2+2]
=1/2*ln(x^2+2x+3)-根号2*[arctan(x+1)/根号2]+C
=ln[根号(x^2+2x+3)]-根号2*[arctan(x+1)/根号2]+C
原式=∫(x+1-2)/(x^2+2x+3) dx
=∫(x+1)dx/(x^2+2x+3)-∫2dx/[(x+1)^2+2]
=1/2*∫d(x^2+2x+3)/(x^2+2x+3)-2∫d(x+1)/[(x+1)^2+2]
=1/2*ln(x^2+2x+3)-根号2*[arctan(x+1)/根号2]+C
=ln[根号(x^2+2x+3)]-根号2*[arctan(x+1)/根号2]+C