Can anybody show me how to integrate x^2*exp(-x^2) between the limits 0 to infinity(symbol=00) and 1.5 to infinity with detail steps. I want this by using error function table. I know the 'multiplying integral method'. Here is what I did so far int(0,00) x^2*exp(-x^2) =x^2*int(0,00)exp(-x^2)-int(0,00)[2*x*int(0,00)exp(-x^2)] =x^2(pi^0.5/2)-int(0,00)[2*x*(pi^0.5/2)] ...first term also between (0,00) This seems to be giving 00! Where am I missing? Thanks. Also please show me how to do this between limits (1.5,00) with error function tables.