∫﹙x²*a^x﹚dx=1/lnx*∫x²da^x=x^2*a^x/lna-2/lnx*∫xa^xdx=x^2*a^x/lna-2/(lnx)^2*∫xda^x=x^2*a^x/lna-2x*a^x/(lnx)^2+2/(lnx)^2∫a^xdx=x^2*a^x/lna-2x*a^x/(lnx)^2+2a^x/(lnx)^3+C