MathematicsAlgebraA-Level
EdexcelAPAbiturAQABaccalauréat GénéralBachilleratoCambridgeCAPS

Remainder theorem Calculator

Find the remainder when a polynomial is divided by (x−a).

Use the free calculatorCheck the variablesOpen the advanced solver
This is the free calculator preview. Advanced walkthroughs stay in the app.
Result
Ready
Function Value

Formula first

Overview

The Remainder Theorem provides a direct method for calculating the remainder of a polynomial division by a linear factor without performing the full division process. It states that when a polynomial f(x) is divided by a linear divisor in the form (x - a), the remainder is equal to the value of the polynomial evaluated at a.

Symbols

Variables

a = Value a, f(a) = Function Value

Value a
Function Value

Apply it well

When To Use

When to use: Use this theorem when you need to find the remainder of a polynomial division specifically by a linear divisor of the form (x - a). It is a highly efficient shortcut when the quotient itself is not required, saving time compared to long or synthetic division.

Why it matters: This theorem forms the logical basis for the Factor Theorem, which is essential for solving algebraic equations and factoring high-degree polynomials. In computational science, it helps in the development of algorithms for error detection and polynomial interpolation.

Avoid these traps

Common Mistakes

  • Evaluating f(-a) instead of f(a).
  • Confusing divisor (x-a).

One free problem

Practice Problem

Calculate the remainder when the polynomial f(x) = x³ - 4x² + 2x - 5 is divided by (x - 3).

Value a3
fx_expressionx^3 - 4*x^2 + 2*x - 5

Solve for:

Hint: Substitute the value x = 3 into the function f(x).

The full worked solution stays in the interactive walkthrough.

References

Sources

  1. Wikipedia: Remainder theorem
  2. Stewart, J. (2015). Calculus: Early Transcendentals. Cengage Learning.
  3. Britannica: Remainder theorem
  4. Stewart, James. Calculus: Early Transcendentals
  5. Stewart, Redlin, and Watson, Precalculus: Mathematics for Calculus, 7th ed.
  6. OCR A-Level Mathematics — Pure (Algebra)