What do the variables in the quadratic formula mean?

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What do the variables in the quadratic formula mean?

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Answer 1 · 2014-11-03T03:31:02

The quadratic formula uses the coefficients of the quadratic equation in standard form when it is equal to zero (y = 0). A quadratic equation in standard form looks like $y= ax^2 + bx + c$ . The quadratic formula is $x = (-b +- sqrt(b^2 - 4ac))/(2a)$ , when y = 0.

Here is an example of how the coefficients of the quadratic equation are used as variables in the quadratic formula:

$0 = 2x^2 + 5x + 3$
This means a = 2, b = 5, and c = 3.

So the quadratic formula becomes:
$x = (-5 +- sqrt(5^2 - 4(2)(3)))/(2*2)$

$x = (-5 +- sqrt(25 - 4(2)(3)))/(2*2)$

$x = (-5 +- sqrt(25 - 24))/(2*2)$

$x = (-5 +- sqrt(1))/(2*2)$

$x = (-5 +- 1)/(2*2)$

$x = (-5 +- 1)/(4)$

$x = (-5 + 1)/(4)$ and $x = (-5 - 1)/(4)$

$x = -4/4 and x = -6/4$

$x = -1 and x = -3/2$

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What do the variables in the quadratic formula mean?

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