My office mate uses Microsoft Word to work out equations. It's easy to copy and paste equation line by line and just do a single manipulation each line. The benefit is you won't be missing factors when copying to next line, when compared with paper and pen.
Is there an easy way to manipulate equations on a GNU/Linux computer?
I tried OpenOffice, Lyx and this other LaTeX add on that renders equations right away. But most had been clunky.
*** I want to cut and paste the rendered LaTeX equation. I don't want to look at a really long latex equation before it's rendered to see which parts to cut and paste because I will get lost.