Uploaded December 2013 | Updated September 2026, 14 hours ago

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Original by DorFuchs: youtube.com/watch?v=tRblwTsX6hQ

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Lyrics:

Have you ever tried to solve an equation with a square?
Then you know it can be hard, but all of them share
a simple way to solve them, may the have one, two
or even no solution, and it's not difficult to do.

The first thing that you need to do is rearrange it to
an equation that reads "x to the two plus px plus q
equals zero". And once it looks like this then you're not far
from solving x, by using the p-q-formula.


X is minus p halfs plus or minus the squareroot of
p halfs squared minus q.
X is minus p halfs plus or minus the squareroot of
p halfs squared minus q.


Well that's all fine and dandy but why does it even work?
Of course I'm gonna tell you, I'm not some kind of jerk:
When you put your equation in the way I told you to:
You can add p halfs (squared) on both sides and subtract the q.

The first binomial formula can now be used right here
and to get rid of the square we take the root, but it is clear
that it could be plus or minus and if we only look at one,
we might lose a solution, subtract the p halfs and you're done.


X is minus p halfs plus or minus the squareroot of
p halfs squared minus q.
X is minus p halfs plus or minus the squareroot of
p halfs squared minus q.

X is minus p halfs plus or minus the squareroot of
p halfs squared minus q.
X is minus p halfs plus or minus the squareroot of
p halfs squared minus q.