Table of contents
- 0. Review of Algebra4h 16m
- 1. Equations & Inequalities3h 18m
- 2. Graphs of Equations43m
- 3. Functions2h 17m
- 4. Polynomial Functions1h 44m
- 5. Rational Functions1h 23m
- 6. Exponential & Logarithmic Functions2h 28m
- 7. Systems of Equations & Matrices4h 6m
- 8. Conic Sections2h 23m
- 9. Sequences, Series, & Induction1h 19m
- 10. Combinatorics & Probability1h 45m
1. Equations & Inequalities
Linear Inequalities
Problem 50c
Textbook Question
Solve each quadratic inequality. Give the solution set in interval notation. See Exam-ples 5 and 6. x^2>16
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1
Rewrite the inequality as a quadratic equation: \(x^2 = 16\).
Solve the quadratic equation \(x^2 = 16\) by taking the square root of both sides, which gives \(x = 4\) and \(x = -4\).
These solutions divide the number line into three intervals: \((-\infty, -4)\), \((-4, 4)\), and \((4, \infty)\).
Test a point from each interval in the original inequality \(x^2 > 16\) to determine which intervals satisfy the inequality.
Based on the test results, write the solution set in interval notation, including only the intervals where the inequality holds true.
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Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Quadratic Inequalities
Quadratic inequalities are expressions that involve a quadratic polynomial set in relation to a value, typically using inequality symbols such as '>', '<', '≥', or '≤'. To solve these inequalities, one must determine the values of the variable that satisfy the inequality, often by finding the roots of the corresponding quadratic equation and testing intervals.
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Nonlinear Inequalities
Interval Notation
Interval notation is a mathematical notation used to represent a range of values. It uses parentheses and brackets to indicate whether endpoints are included (closed intervals) or excluded (open intervals). For example, the interval (2, 5] includes all numbers greater than 2 and up to and including 5.
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Graphing Quadratics
Graphing quadratics involves plotting the quadratic function on a coordinate plane to visualize its shape, which is a parabola. The vertex, axis of symmetry, and intercepts are key features that help in understanding the behavior of the quadratic function, particularly in determining where it is above or below a certain value, which is essential for solving inequalities.
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