Please solve this question with solution. Thanks?

Sol
與x軸所夾面積
∫(－1 to 2)_x^2+1dx
=(x^3/3+x)｜(－1 to 2)
=(2^3/3+2)－[－-1)^3/3－1]
=(8/3+2)－(－1/3－1)
=14/3+4/3
=6
(E)