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Step-by-Step Guidance for Solving Quadratic Inequalities from Graphs

Study Guide - Smart Notes

Tailored notes based on your materials, expanded with key definitions, examples, and context.

Q1. For the given graph of , answer the following:

  • a) Where does ?

  • b) Where does ?

  • c) Where does ?

Background

Topic: Quadratic Inequalities and Graph Interpretation

This question tests your ability to interpret the graph of a quadratic function and determine where the function is zero, positive, or negative. This is a key skill in college algebra, especially when solving inequalities involving quadratics.

Key Terms and Concepts:

  • Zero of a function: The x-values where (the graph crosses the x-axis).

  • Positive values: The intervals where the graph is above the x-axis ().

  • Negative values: The intervals where the graph is below the x-axis ().

  • Quadratic function: A function of the form whose graph is a parabola.

Step-by-Step Guidance

  1. Examine the graph and identify the points where the curve crosses the x-axis. These are the solutions to (the zeros or roots of the function).

  2. Look for the intervals where the graph is above the x-axis. In these intervals, . For , include both the intervals above the x-axis and the points where the graph touches or crosses the x-axis.

  3. Identify the intervals where the graph is below the x-axis. In these intervals, .

  4. Write your answers using interval notation, based on the x-values you observe from the graph for each part (a, b, c).

Try solving on your own before revealing the answer!

Final Answer:

a) at the x-values where the graph crosses the x-axis (list these values).

b) for x-values where the graph is below the x-axis (write the interval(s)).

c) for x-values where the graph is on or above the x-axis (write the interval(s)).

These answers are found by carefully reading the graph and noting the relevant x-values for each condition.

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