f(x)=u(x)*v(x)f'(x)=u'(x)*v(x)+u(x)*v'(x)y=x^3log5(x)y'=(x^3)'log5(x)+x^3[log5(x)]'=3x^2log5(x)+x^3*[1/(xln5)]=3x^2log5(x)+x^2/ln5
