Addendum (I'm a newbie and couldn't see a way to edit the original post):
I wondered why S,T always turn out to be integers when you calculate them by solving simultaneous equations.
The formulas for S,T are (-b+root(b^2-4ac))/2 and (-b-root(b^2-4ac)/2).
The trick is that b^2-4ac is only even...
Hi! I came across the below thread where a user ('krackers') asked for a proof of the PSF factorising method for quadratic equations.
The thread is now closed so I'd like to post my proof here.
(The proof considers the simplest case where there are no common factors for a,b,c in the quadratic...