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Polynomial Calculator

Evaluate ax² + bx + c at a given x.

Worth Knowing

Evaluating ax² + bx + c at a given x is a direct substitution, but the efficient way to do it — factoring as (ax + b)x + c, known as Horner's method — minimizes the number of multiplications and is how software actually evaluates polynomials. Quadratics like this trace a parabola, whose direction and width are set by the leading coefficient a; the sign of a alone tells you whether the curve opens upward or downward.

How to Use

  1. Enter a into the first field of the Polynomial Calculator.
  2. Fill in the rest: b, c, x.
  3. Your result appears instantly as you type — there's no submit button or page reload.

Frequently Asked Questions