求定积分∫(0,1) 1/(x^2+2x+2)dx
问题描述：
求定积分∫(0,1) 1/(x^2+2x+2)dx
答
原式=∫(0→1)dx/((x+1)^2+1)
=∫(0→1)d(x+1)/((x+1)^2+1)
=arctan(x+1)|(0→1)
=arctan2-π/4