∫x/(x^2＋x＋1) dx= (1/2)∫ dln(x^2+x+1) -(1/2)∫1/(x^2＋x＋1) dx= (1/2)ln(x^2+x+1) -(1/2)∫1/(x^2＋x＋1) dx x^2＋x＋1= (x+1/2)^2+3/4letx+1/2 = (√3/2) tanadx =(√3/2) (seca)^2 da∫1/(x^2＋x＋1) dx=∫...