A level Maths and Further Maths useful tricks

I've noticed that the difference of two cubes pops up on occasion, (a-b)(a²+ab+b²) = a³ - b³

Does anybody have any other useful tricks that aren't on the specification?

You must have seen the STEP tricks thread (where this exact trick you've mentioned has been posted before) - surely we don't need another for the same syllabus.

How many of the STEP tricks can be used on a standard A level M/FM paper?

All of them.

Okay I didn't word that particularly well. Are we ever given the opportunity to use many of them? If there are a few please list them.

I've listed a ton on the STEP version already, they come up just as often on a standard A-Level Paper as they do on a STEP one, speaking from personal experience - that's what lets me finish FM papers off in c. 45 minutes - so I'm not going to rewrite something I've already written on another thread.

Does anyone here know Hero'sx formula for finding area of triangles?

$\displaystyle A = \sqrt{s(s-a)(s-b)(s-c)}$ for a triangle with sides $a,b, c$ and $S = \frac{a + b + c}{2}$.

I meant is it (Heron's ) still taught at schools?

I know Lagragian Multipliers has been off the syllabus years ago.