Question

How do you evaluate the definite integral `int x^2 dx` from `[1,2]`?

Answer 1

`int_1^2x^2dx=7/3`

Explanation:

As `d/(dx)x^3=3x^2`

`int_1^2x^2dx=|x^3/3|_1^2`

= `(2^3/3-1^3/3)`

= `8/3-1/3=7/3`