WHY do you need to know it? WHERE did it come from? HOW can I remember it? Why can't math be more fun? WHEN can I use it? The quadratic formula is practically a rite of passage in high school mathematics, and possibly the most famous formula ever taught...This rap will break it all down and leave you groovin' to math on beat.
Lyrics by Mr. Calford (c) 2012:
(Music provided by Nebula at www.beats365.com)
So you're facing a quadratic looking all mean and scary
It's set to equal zero but the roots are looking hairy
Not integers is what I mean by that
you tried to factor it down but struck out at bat
Now you're contemplating just completing the square
Get the vertex form and solve it for x from there
but that's a lot of work, do you think paper grows on trees?
Gotta be an easier way, like Apple over PC
So you flip open you text book and read to your delight
there's a formula that you can use and everything is tight
One size fits all if it's in standard form,
Even if it could factor this would take it by storm!
Finds both the roots with a giant calculation
It looks intimidating but with practice it can be your friend
All you need to use it is to know your a, b, c's
Coefficients I mean, and watch the negatives please!
Make the roots clear like Reactin to a sinus
they're negative b followed by a plus or minus
A big square root with b squared inside
gotta keep that root going 'fore ya good to divide It'd...
..be hot like ginger root if not 4 a c
The numerator's done lets move along to underneath
It's a short divisor like the stubble on a face
Like an Energizer keep it going double A (yes!)
Now the curriculum makes it clear you're not required to derive it
But I'mma pop open the algebraic hood and demystify it
The general standard form quadratic poses limitations
X is hard to isolate when it lives in two locations
Get a number 2 pencil and a gigantic piece of paper
'sbout to be an algebra drive by duck for cover or listen clear
Start with the general standard form equation factor out the A
From the first two terms but move the C, subtract it out the way
While we're at it move the A divide it cleanly from both sides
Now we're left with a fractional coefficient for the x but please don't cry
We to factor down the X till it's contained in a perfect square
We need to add the square of half B over A to both sides to get there--
Factor on the left on the right apply the power to the fraction
Common denominator action so we can do subtraction
Then combat the square taking the root of both the sides
Subtract B over 2A put it together and we've arrived!
When the numbers look ugly and they got you feeling blue
The equation doesn't factor you don't know what to do...
(I'm telling you) x is equal to negative b, plus or minus the root of the following,
b squared take away 4 a c, then divide all of that by 2a underneath.
This formula will guide you, steady follow it through
It's a method guaranteed to deliver the roots...
x is equal to negative b, plus or minus the root of the following
b squared take away 4 a c, divide all of that by 2a underneath