Key Concepts in Function Operations

Jun 3, 2025

Math Practice Test

Key Concepts and Operations

Operations with Functions

  • G(-2) - H(-2):
    • G(-2) = 2(-2) - 2 = -4 - 2 = -6.
    • H(-2) = (-2)^2 + (-2) = 4 - 2 = 2.
    • So, G(-2) - H(-2) = -6 - 2 = -8.

Difference of Functions

  • H(t) - G(t):
    • Given H(t) = -t + 1 and G(t) = 4t + 2.
    • Combine like terms:
      • (-t - 4t) = -5t.
      • (1 - 2) = -1.
    • Result: -5t - 1.

Substitution in Functions

  • F - G with n/2:
    • Substitute n/2 into the functions:
      • F(n/2) = 4(n/2) - 3.
      • G(n/2) = 3 + 5(n/2)^2.
    • Simplify the expressions and find like terms.

Graphing Functions Domains

  • Piecewise Function:
    • For x <= 0: y = -x - 1 (slope: -1).
    • For 0 < x < 4: y = -4 (y-constant across the domain).
    • For x >= 4: y = -2.

Transformations of Graphs

  • Graph Translations and Dilations:
    • Translation: Shift the graph down by 2 units.
    • Dilation or compression: Scale the graph vertically by a factor (e.g., 1/3).

Square Root and Absolute Value Transformations

  • Graph Reflections:
    • Reflection across the y-axis or x-axis depending on inside/outside negative signs.
  • Absolute Value Function:
    • New zero at x = 3.

Quadratic Functions and Graphs

  • Vertex and Intercepts: Quadratic Equations:
    • Determine vertices from symmetrical points (midpoints between intercepts).
    • Use standard form and factorization to find x-intercepts.

Analyzing Quadratic Inequalities

  • Inequality Solving:
    • Determine where a quadratic is less than or equal to zero by testing points in different segments of the domain (using test points around critical values).
    • Utilize endpoints of test intervals based on where the function equals zero.

Practice with Graphs and Equations

  • Sketch and Identify:
    • Sketch quadratics based on intercepts and vertex.
    • Identify x-intercepts as solutions of the quadratic equation.

Considerations for Function Behavior

  • Increasing and Decreasing Intervals:
    • Identify where functions are increasing or decreasing by analyzing the graph over intervals.
    • Consider continuity and smoothness of functions in transition.