Algebra 3/4

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

Basic Concepts

Polynomial Functions

What Are Polynomial Functions?

Polynomial functions are mathematical expressions involving variables raised to whole number powers, all combined using addition, subtraction, and multiplication. The general form looks like this:

\[ f(x) = a_nx^n + a_{n-1}x^{n-1} + \cdots + a_1x + a_0 \]

where \( a_n, a_{n-1}, \ldots, a_0 \) are constants, and \( n \) is a non-negative integer called the degree.

Key Features

  • Degree: The highest exponent of the variable.
  • Leading Coefficient: The coefficient of the term with the highest degree.
  • End Behavior: How the graph behaves as \( x \) approaches infinity or negative infinity.

Why Are They Important?

Polynomial functions model real-world situations, like predicting profits, tracking the trajectory of a ball, or understanding population growth.

Graphing Polynomial Functions

The shape of a polynomial graph depends on its degree and leading coefficient. Higher-degree polynomials have more turning points and can cross the x-axis more times.

Working with Polynomials

You can add, subtract, multiply, and even divide polynomials. Polynomial division is especially useful for simplifying expressions.

Key Formula

\[f(x) = a_nx^n + a_{n-1}x^{n-1} + ... + a_0\]

Examples

  • The function \( f(x) = 2x^3 - 5x^2 + x - 7 \) is a cubic polynomial.

  • The graph of \( g(x) = x^2 - 4 \) is a parabola opening upwards.

In a Nutshell

Polynomial functions are algebraic expressions with variables raised to whole number powers.

Key Terms

Degree
The highest exponent in a polynomial.
Leading Coefficient
The coefficient of the term with the highest degree.
Zero
A value of \( x \) where the polynomial equals zero.