Synthetic Division Calculator

Divide a cubic ax³ + bx² + cx + d by (x − r).

Quotient x² coeff 1
Quotient x coeff -5
Quotient constant 6
Remainder 0

Formula: Bring down, multiply by r, add — repeat

Step-by-step with your numbers:
1. Values used:
2. a (x³) = 1
3. b (x²) = -6
4. c (x) = 11
5. d (constant) = -6
6. Divisor root r = 1
7.
8. Quotient x² coeff = 1
9. Quotient x coeff = a (x³) + b (x²) = 1 + -6 = -5
10. Quotient constant = 6
11. Remainder = 0
Did we solve your problem today?

Synthetic division is a fast shortcut for dividing a polynomial by a linear factor (x − r).

How the Math Works

Synthetic division simplifies polynomial division by replacing long division with a streamlined arithmetic process. When dividing a cubic polynomial ax³ + bx² + cx + d by (x − r), the method uses only the coefficients and the value of r. Starting with the leading coefficient a, each step involves 'bringing down' the current value, multiplying it by r, and adding it to the next coefficient. This cycle repeats until all coefficients are processed, yielding the quotient polynomial and remainder efficiently through basic operations like multiplication and addition.

Practical Applications

To use the Synthetic Division Calculator, input the coefficients a, b, c, d of your cubic polynomial and the value r from the divisor (x − r). The calculator automates the 'bring down, multiply by r, add' sequence, displaying each intermediate step clearly. For example, dividing 2x³ + 3x² - 5x + 7 by (x - 2) requires entering coefficients [2, 3, -5, 7] and r = 2. The result provides the quotient (2x² + 7x + 9) and remainder (25), saving time and reducing errors in manual calculations.

Day-to-Day Use

Synthetic division is invaluable for solving real-world problems modeled by polynomials, such as optimizing engineering designs or analyzing electrical circuits. It also streamlines academic tasks like factoring polynomials for exams or verifying solutions to equations. By mastering this technique, students and professionals can quickly assess polynomial behavior, find roots, or simplify complex calculations in fields ranging from physics to computer science, making it a versatile tool for both education and practical problem-solving.

Worked example

(x³ − 6x² + 11x − 6) ÷ (x − 1) → quotient x² − 5x + 6, remainder 0.

FAQ

What does a zero remainder mean?

r is a root, so (x − r) is a factor of the polynomial.