Answer:
as we know, the integral of
is

so, the integral of x.
will be found as follows:
here, we will use a trick called 'integration by parts'
let x = u and
= v
∫uv dx = u∫v dx - ∫[(du/dx)* ∫v dx] dx
∫x.
dx = x∫
- ∫[(dx/dx) * ∫
dx ] dx
∫x.
dx = x*
- 1 *

=
( x - 1 )