Calculadora de Divisão Sintética (por x − r)
- Created by
- Renato Passos, Eng. de Software
- Reviewed by
- Renato Passos, Eng. de Software
Last updated: Apr 18, 2026
Formula
P(x) ÷ (x − r) via tabela de Briot-Ruffini
About this calculator
The synthetic division calculator is a practical tool for performing polynomial division using the Briot-Ruffini method, specifically for divisors of the form (x − r). It accepts a degree-2 polynomial (a₂x² + a₁x + a₀) and a real value r, returning the quotient and remainder. The process is faster than traditional long division.
The algorithm works by arranging the polynomial coefficients (a₂, a₁, a₀) in a row and performing successive additions and multiplications with the value r below. The result is a degree-1 quotient (b₁x + b₀) and a constant remainder. For example, dividing 2x² + 3x + 1 by (x − 1) yields quotient 2x + 5 and remainder 6.
Use this calculator when you need to quickly check if (x − r) is a factor of the polynomial (remainder zero) or to simplify algebraic expressions. It is useful in algebra homework, root finding, and engineering problems involving polynomials. Synthetic division is a standard method in calculus and linear algebra courses.
Caution: ensure the polynomial is in standard form (descending degree) and that all terms, including those with zero coefficients, are included. The divisor must be exactly (x − r); for divisors like (x + 2), use r = −2. The method applies only to linear divisors. Verify that the coefficients are real numbers.
Frequently asked questions
What is synthetic division?
It is a simplified method for dividing polynomials by binomials of the form (x − r), using only coefficients. It is faster than long division.
How to use the calculator?
Enter the coefficients a₂, a₁, a₀ and the value of r. Click calculate to get the quotient and remainder.
What does a zero remainder mean?
It means (x − r) is a factor of the polynomial, i.e., r is a root of the polynomial.
Can I use it for polynomials of degree higher than 2?
This version only accepts degree-2 polynomials. For higher degrees, the method is similar but requires more coefficients.
What if the divisor is (x + 2)?
Use r = −2, since (x + 2) = (x − (−2)). The method requires the form (x − r).