Question 391285: what is the quadratic formula?
what is the origin of the quadratic formula? Found 2 solutions by richard1234, solver91311:Answer by richard1234(7193) (Show Source):
You can put this solution on YOUR website! The quadratic formula says that the two roots of any second degree polynomial {{ax^2 + bx + c}}} are .
It is possible to derive the quadratic formula by completing the square. This Wikipedia article lists multiple ways to derive the formula:
The quadratic formula gives the general solution of a quadratic equation. The formula was developed by completeing the square on the general quadratic equation:
Move the constant term to the RHS:
Divide by the lead coefficient:
Divide the coefficient on the 1st degree term by 2, square the result, then add that result to both sides of the equation:
Apply the LCD and complete the sum in the RHS:
Factor the perfect square in the LHS:
Take the square root remembering to consider both the positive and negative root:
Add to both sides:
John
My calculator said it, I believe it, that settles it