Question

How do you find the definite integral of `int (x^2 + x) dx` from `[1,3]`?

Answer 1

It is

#int_1^3 (x^2+x)dx=int_1^3 d/dx[x^3/3+x^2/2]dx= [x^3/3+x^2/2]_1^3=9+9/2-(1/3+1/2)=38/3#