What is the quadratic formula?

x = (−b ± √(b²−4ac)) / (2a). Discriminant b²−4ac determines number of real roots.

Online Quadratic Equation Calculator

Solve ax² + bx + c = 0. Enter coefficients a, b, c for real roots.

a (x²)

b (x)

What is the quadratic formula?: x = (−b ± √(b²−4ac)) / (2a). Discriminant b²−4ac determines number of real roots.

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Convert Celsius to Fahrenheit and Fahrenheit to Celsius instantly. Free temperature converter.

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Calculate tip and split the bill. Enter bill amount, tip percentage, and number of people.

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Convert numbers to Roman numerals and Roman numerals to numbers. Supports 1–3999.

Combinations Calculator

Calculate C(n,r) — the number of ways to choose r items from n without order. Uses n!/(r!(n-r)!).

Combinations with Replacement Calculator

Calculate the number of ways to choose r items from n with repetition allowed. Formula: C(n+r-1, r).

Even Permutations Calculator

Count how many permutations of n objects are even (expressible as an even number of swaps). For n ≥ 2, equals n!/2.