remainder theorem

NOVEMBER 14, 2023

What is the Remainder Theorem in Math? Definition

The Remainder Theorem is a concept in mathematics that helps us determine the remainder when a polynomial is divided by a linear factor. It provides a shortcut method to find the remainder without performing long division.

History of Remainder Theorem

The concept of the Remainder Theorem can be traced back to ancient times, where mathematicians used various methods to find remainders. However, the formalization of the theorem is credited to the French mathematician Pierre de Fermat in the 17th century. Fermat's work laid the foundation for the development of modern algebraic concepts, including the Remainder Theorem.

Grade Level for Remainder Theorem

The Remainder Theorem is typically introduced in high school mathematics, specifically in algebra courses. It is commonly taught in grades 9 or 10, depending on the curriculum.

Knowledge Points in Remainder Theorem and Detailed Explanation Step by Step

The Remainder Theorem involves the division of a polynomial by a linear factor of the form (x - a), where 'a' is a constant. The theorem states that if we divide a polynomial f(x) by (x - a), the remainder will be equal to f(a).

To understand this concept step by step, let's consider an example. Suppose we have a polynomial f(x) = 2x^3 - 5x^2 + 3x - 1, and we want to find the remainder when f(x) is divided by (x - 2).

  1. Substitute the value of 'a' from the linear factor into the polynomial: f(2) = 2(2)^3 - 5(2)^2 + 3(2) - 1.
  2. Simplify the expression: f(2) = 16 - 20 + 6 - 1 = 1.
  3. The remainder when f(x) is divided by (x - 2) is 1.

This step-by-step process allows us to find the remainder efficiently without performing long division.

Types of Remainder Theorem

There is only one type of Remainder Theorem, which involves dividing a polynomial by a linear factor (x - a).

Properties of Remainder Theorem

The Remainder Theorem has a few important properties:

  1. The remainder will always be a constant value.
  2. If the remainder is zero, it implies that the linear factor (x - a) is a factor of the polynomial.
  3. The degree of the remainder will always be less than the degree of the divisor (x - a).

How to Find or Calculate Remainder Theorem?

To find or calculate the remainder using the Remainder Theorem, follow these steps:

  1. Substitute the value of 'a' from the linear factor into the polynomial.
  2. Simplify the expression to obtain the remainder.

Formula or Equation for Remainder Theorem

The formula for the Remainder Theorem can be expressed as follows:

If a polynomial f(x) is divided by (x - a), the remainder R is given by R = f(a).

How to Apply the Remainder Theorem Formula or Equation?

To apply the Remainder Theorem formula, substitute the value of 'a' into the polynomial and evaluate it. The result will be the remainder.

Symbol or Abbreviation for Remainder Theorem

There is no specific symbol or abbreviation for the Remainder Theorem. It is commonly referred to as the "Remainder Theorem" in mathematical literature.

Methods for Remainder Theorem

The main method for applying the Remainder Theorem is substitution. By substituting the value of 'a' into the polynomial, we can find the remainder.

More than 3 Solved Examples on Remainder Theorem

Example 1: Find the remainder when f(x) = 3x^4 - 2x^3 + 5x^2 - 4x + 1 is divided by (x - 1).

Solution: Substitute 'a' = 1 into the polynomial: f(1) = 3(1)^4 - 2(1)^3 + 5(1)^2 - 4(1) + 1 = 3 - 2 + 5 - 4 + 1 = 3.

The remainder is 3.

Example 2: Find the remainder when f(x) = 2x^3 + 7x^2 - 3x + 2 is divided by (x + 2).

Solution: Substitute 'a' = -2 into the polynomial: f(-2) = 2(-2)^3 + 7(-2)^2 - 3(-2) + 2 = -16 + 28 + 6 + 2 = 20.

The remainder is 20.

Example 3: Find the remainder when f(x) = x^5 - 4x^4 + 3x^3 - 2x^2 + 5x - 1 is divided by (x + 1).

Solution: Substitute 'a' = -1 into the polynomial: f(-1) = (-1)^5 - 4(-1)^4 + 3(-1)^3 - 2(-1)^2 + 5(-1) - 1 = -1 + 4 - 3 - 2 - 5 - 1 = -8.

The remainder is -8.

Practice Problems on Remainder Theorem

  1. Find the remainder when f(x) = 4x^3 - 3x^2 + 2x - 1 is divided by (x - 3).
  2. Find the remainder when f(x) = 5x^4 + 2x^3 - 7x^2 + 4x + 3 is divided by (x + 4).
  3. Find the remainder when f(x) = 2x^2 - 5x + 3 is divided by (x - 2).

FAQ on Remainder Theorem

Question: What is the Remainder Theorem? Answer: The Remainder Theorem is a mathematical concept that helps us find the remainder when a polynomial is divided by a linear factor.

Question: How is the Remainder Theorem applied? Answer: The Remainder Theorem is applied by substituting the value of 'a' from the linear factor into the polynomial and evaluating it to find the remainder.

Question: What is the formula for the Remainder Theorem? Answer: The formula for the Remainder Theorem is R = f(a), where R represents the remainder and 'a' is the constant value from the linear factor.