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Functions Review and Evaluation Concepts

May 12, 2025

EOC Review Lecture Notes

Understanding Functions

  1. Linear Functions

    • Recognized by constant first differences in Y-values.
    • Example: Increases of 3 every time.
  2. Exponential Functions

    • Recognized by consistent multiplication in Y-values.
    • Example: Multiplying by 4 each time.
  3. Key Function Types

    • Linear, Exponential, and Quadratic functions are crucial.

Evaluating Functions

  • Evaluate function for f(-3):
    • Substitute -3 for x.
    • Example: f(-3) = -8.

Quadratic Functions

  1. Key Features

    • Vertex: Highest/lowest point.
      • Example: (-1, 4)
    • Axis of Symmetry: x = -1
    • Domain: All real numbers.
    • Range: Y ≤ 4
    • End Behavior: Y values go to -∞.
  2. Increasing/Decreasing Intervals

    • Increasing until vertex.
    • Decreasing after vertex.

Solving Systems of Equations

  • Elimination Method
    • Example: Eliminate x variable.
    • Solution: x = 2, y = 2.

Simplifying Expressions

  • Positive Exponents Only
    • Example: x * y⁵ / 3*

Radical Expressions

  • Simplify with One Radical
    • Example: 16 * ∛20*

Graphing Linear Equations

  • Slope-Intercept Form
    • Slope = 3/4
    • Y-intercept = -2

Comparing Functions

  • Slopes and Intercepts
    • Greater slope: G(x)
    • Greater Y-intercept: G(x)
    • Greater X-intercept: f(x)

Writing Inequalities

  • Graph Interpretation
    • Example: y > -x - 2

Solving Absolute Value Equations

  • Setup Two Equations
    • Example: x = 0, x = -1

Simple Interest Calculation

  • Using Formula
    • Example: Amount = $577.50 after 10 years.

System of Equations in Word Problems

  • Set up equations for costs
    • Example costs: Pants = $16.67, Shirts = $16.66

Parabola Equations

  • Vertex and Point Usage
    • Equation example: y = -4x² + 24x - 32

Maximizing Profit with Quadratics

  • Vertex Formula Usage
    • Example: $3.50 per ticket maximizes profit.

Perpendicular Lines

  • Opposite Reciprocal Slopes
    • Equation example: y = -9/2x - 5

Exponential Functions

  • End Behavior Description

    • As X → -∞, Y → -∞
    • As X → ∞, Y → 0
  • Y-Value Changes

    • Y is increasing and getting closer to 0.