Table of contents
- 0. Review of Algebra4h 18m
- 1. Equations & Inequalities3h 18m
- 2. Graphs of Equations1h 43m
- 3. Functions2h 17m
- 4. Polynomial Functions1h 44m
- 5. Rational Functions1h 23m
- 6. Exponential & Logarithmic Functions2h 28m
- 7. Systems of Equations & Matrices4h 5m
- 8. Conic Sections2h 23m
- 9. Sequences, Series, & Induction1h 22m
- 10. Combinatorics & Probability1h 45m
1. Equations & Inequalities
Linear Inequalities
Problem 42
Textbook Question
Solve each quadratic inequality. Give the solution set in interval notation. See Exam-ples 5 and 6. x2-7x+10>0
Verified step by step guidance1
Start by rewriting the inequality: \(x^2 - 7x + 10 > 0\).
Factor the quadratic expression on the left side: \(x^2 - 7x + 10 = (x - 5)(x - 2)\).
Determine the critical points by setting each factor equal to zero: \(x - 5 = 0\) gives \(x = 5\), and \(x - 2 = 0\) gives \(x = 2\).
Use the critical points to divide the number line into three intervals: \((-\infty, 2)\), \((2, 5)\), and \((5, \infty)\). Test a value from each interval in the inequality \((x - 5)(x - 2) > 0\) to see where the product is positive.
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
A quadratic inequality involves a quadratic expression compared to zero using inequality symbols (>, <, ≥, ≤). Solving it means finding all x-values that make the inequality true. This often requires analyzing the sign of the quadratic expression over different intervals.
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Nonlinear Inequalities
Factoring Quadratic Expressions
Factoring rewrites a quadratic expression as a product of two binomials. For example, x² - 7x + 10 factors to (x - 5)(x - 2). Factoring helps identify the roots or zeros of the quadratic, which are critical points for testing intervals in inequalities.
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Interval Notation and Sign Analysis
Interval notation expresses solution sets as ranges of values, such as (−∞, 2) ∪ (5, ∞). After finding roots, sign analysis tests the quadratic’s positivity or negativity in intervals between and beyond the roots to determine where the inequality holds.
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Interval Notation
Related Videos
Related Practice
Textbook Question
Answer the following. Why can 3 not be in the solution set of 14x+9 / x-3 < 0? (Do not solve the inequality.)
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