Top definition
Arguably the second most popular mathematical formula after the Pythagorean theorem, which gives the zeros (or roots) of the quadratic equation ax² + bx + c = 0 in terms of a, b, and c.
A less well-known quadratic formula to ax² + bx + c = 0, a ≠ 0 among math teachers and students is x = 2c ÷ –b ± √(b² – 4ac), instead of the traditional x = –b ± √(b² – 4ac) ÷ 2a—any form of the formula can be obtained from the other by rationalizing the denominator.
via giphy
by MathPlus April 14, 2017
2
x = -b plus or minus the square root of (b^2 - 4ac) all divided by 2a. Used for quadratic equations where you can't factor. the equation is ax^2 + bx + c.
Fuck the quadratic equation I have a graphing calculator.
by Yo fucking momma December 17, 2003
3
A handy formula easily memorized by repetition. It is used in many instances, such as trying to find the roots of an equation, or solving an equation that will not factor with integers.

To solve using the Quadratic Formula:

In any equation

ax^2+bx+c,

The roots can be found by substituting into:

-b(+,-)sqrt(b^2-4ac)/2a

OR

Negative "B" plus or minus the square root of "B" squared minus 4(a)(c), all divided by 2(a).
To solve using the Quadratic Formula:

In any equation

ax^2+bx+c,

The roots can be found by substituting into:

-b(+,-)sqrt(b^2-4ac)/2a

OR

Negative "B" plus or minus the square root of "B" squared minus 4(a)(c), all divided by 2(a).

EX:

Hm..

10x^2+13X-5

-13(+,-)sqrt(169+200)/20
>_>
In other words, by substituting the numbers in, you get 13(+,-)sqrt(369)/20.

As you may or may not have guessed, this gives you a very nasty number, which should be approximated and rounded to the nearest thousandth.
by "Seagaia" May 19, 2005
4
ex equals the opposite of B plus or minus the square root of B squared minus four AC all over two A (to the tune of the mulbary bush the monkey chases the weasle)
x = -B(+/-)(squaroot of:)(b^2 - 4AC)
----------------------------------
2A
when the equation is
0=Ax^2 + Bx + C
by mathfreakazoid November 11, 2005