答：∫ x³√(x²+2) dx=(1/2) ∫ x²√(x²+2) dx²=(1/2)∫ (x²+2-2)√(x²+2) d(x²+2)=(1/2) ∫ (x²+2)^(3/2)-2√(x²+2) d(x²+2)=(1/2)*(2/5)*(x²+2)^(5/...