I am learning to derive the Taylor Series for $f(x)$, and I cannot remember how to do the following integral. 

$\int\_{x\_0}^x \left(x-x\_0\right) \, dx $ to get the following solution $=\frac{\left(x-x\_0\right){}^2}{2!}\ $ 

I have been out of university for many years. I believe I would use substitution, but I thought I would get some expert help since I need to work on other projects and multi-task. 

I saw the above solution at Wolfram Alpha's description of Taylor series expansion[1]. 

Please be generous with steps and lead me to the appropriate integral method! 

References: 

[1] Wolfram Mathworld. Taylor Series. Retrieved (2015, Dec. 17). Mathworld.wolfram[online]. Available from: <http://mathworld.wolfram.com/TaylorSeries.html>