Tag Archives: Quadratic Formula

How to Derive the Quadratic Formula by Solving the Quadratic Equation

This video shows how to derive the quadratic formula by solving the quadratic equation.

This is a step by step solution starting with the quadratic equation.

1) divide through by the coefficient “a”

2)┬ácomplete the square by adding “b^2/(4*a^2)” to both sides

3) subtract “c/a” from both sides of the equation

4)┬átake the square root of both sides of the equation (don’t forget the plus or minus +/- in front of the square root.)

5) combine the fractions under the square root

6) subtract “b/a” from both sides of the equation

7) combine the fractions

We have successfully isolated “x” and therefore derived the quadratic formula from the quadratic equation.