Using the Quadratic Formula Calculator responsibly
Page-specific guidance based on this calculator’s implemented method, inputs, and known limits.
What this result is useful for
The quadratic formula solves equations of the form ax² + bx + c = 0 and reports the nature of the roots from the discriminant. It is useful when factoring is inconvenient or when exact and approximate roots need to be compared.
Assumptions and limits
The leading coefficient must not be zero; otherwise the equation is linear. A negative discriminant produces complex roots. Displayed decimal roots may be rounded even when an exact radical form exists.
How to check the result
Substitute each reported root into the original polynomial and confirm that the result is zero within rounding tolerance. The sum of the roots should equal −b/a and their product should equal c/a.