Algebra 3/4

Algebra 3/4 delves into advanced algebraic concepts, including polynomial functions, rational expressions, and complex numbers.

Advanced Topics

Polynomial Division and the Remainder Theorem

Dividing Polynomials

Just like regular numbers, polynomials can be divided. The two main methods are long division and synthetic division.

Long Division

Set up the division just as you would with numbers. Divide the leading terms, multiply, subtract, and bring down the next term. Repeat until you can't go further.

Synthetic Division

A shortcut for dividing by linear factors like \( x - c \). It involves writing coefficients and performing simple operations to find the quotient and remainder.

The Remainder Theorem

The theorem states: If you divide a polynomial \( f(x) \) by \( x - c \), the remainder is \( f(c) \).

Why Use These?

Polynomial division helps in simplifying expressions and finding factors, while the Remainder Theorem makes evaluating polynomials at specific values super quick.

Key Formula

\[f(x) = (x - c)q(x) + r\]

Examples

  • Dividing \( x^3 - 6x^2 + 11x - 6 \) by \( x - 1 \) using synthetic division gives a remainder of 0.

  • For \( f(x) = 2x^2 + 3x + 5 \), the remainder when divided by \( x - 2 \) is \( f(2) = 2(4) + 3(2) + 5 = 8 + 6 + 5 = 19 \).

In a Nutshell

Polynomial division and the Remainder Theorem help break down polynomials and quickly find remainders.

Key Terms

Synthetic Division
A quick method for dividing polynomials by linear factors.
Remainder Theorem
A rule that gives the remainder of a polynomial division using substitution.