h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

Beeblebrox?

hey, like almost everyone else has said you should include completing the square(please dnt use the completing the square formula, thats just confusing and its easy without it) and factorisation, just as an aside if you want to keep the entry just about the formula,

also i think you should mention that the formula only applies when a does not equal zero, which is obvious but an important point. this emphasisies this only applies to quadratic equations and makes you look clever at the same time.

mention that when c is a minus number, you effectively add 4ac, people get this wrong all the time because they forget that, or simply dont know -*-=+.

if you want to go into general quadratics, you could mention differentiation and coordinate geometry to find the gradient etc.

someone else talked about the discriminant, talk about how if 4ac is more than b*b you have to square root a minus number, technically impossible.
gd luck if ure gonna take this on

SuperSam

Sqrts of negatives are no pröblem if you use complex numbers i²=-1.

HELL

true, but complex numbers aren't very useful for solving quadratic equations, isn't the point of solving quadratics to solve remove the unknown, not add a whole load of new unknowns that don't even exist.

sorry, accidental solve b4 remove

I thought that i²=-1 was considered and 'irrational' number, not a complex one??

Maybe I'm translating from German. Here we call 'em 'complex'. Maybe you have a different terminology over there...

HELL

The square root of -1 (called i) is an imaginary number, as are multiples thereof.

Complex numbers are a combination of real numbers with imaginary numbers, as in 4+2i but I suppose 0+3i is in the set of complex numbers so 3i is both a complex number and an imaginary number.

Irrational numbers are those, like pi and e, which cannot be expressed as a fraction. As in 'not a ratio'.

F

So, in the end, I was not *that* wrong, hah

HELL

And I was not that right !

I'm just wondering if Beeblebrox sorted out his broadband problem...


HELL

apparantly not...

No - I'd say it looks quite un-sorted so far...

Anyone think a move might be in order on this one?

Speller

I'd be on board with a move to the Flea Market.

That seems reasonable to me. Seconded

Great, email sending off.