"Bill Grey" wrote in
:


"Tom" wrote in message
.253...
Martin wrote in
:

In real life being able to instantly recall a product is better than
knowing how to derive it from scratch.


And much better than either is knowing how and
when to use/apply it, and to use the right tool
to get the correct answer.


Try solving a quadratic equation using the "formla" method, oh damn! -
you've forgotten the formula (shame)

Now use the "completing the square" logical method.- no formulae
involved.

Nice to kow how it really is done.

But that is less trivial for x^2 + x + 1