∫(1到+∞)1/(x²-x+1)dx
=lim(u→+∞)∫(1到u)1/(x²-x+1)dx
=lim(u→+∞)∫(1到u)1/[(x-1/2)²+3/4]dx
=lim(u→+∞)2/√3[arctan(2x-1)/√3]|(1到u)
=2√3π/9
∫(1到+∞)1/(x²-x+1)dx
=lim(u→+∞)∫(1到u)1/(x²-x+1)dx
=lim(u→+∞)∫(1到u)1/[(x-1/2)²+3/4]dx
=lim(u→+∞)2/√3[arctan(2x-1)/√3]|(1到u)
=2√3π/9