Solve each inequality in Exercises 86–91 using a graphing utility. 2x2 + 5x - 3 ≤ 0
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 21
Textbook Question
Solve each polynomial inequality in Exercises 1–42 and graph the solution set on a real number line. Express each solution set in interval notation.
Verified step by step guidance1
Start by rewriting the inequality: \$2x^{2} + 3x > 0$.
Factor the left-hand side expression: \(x(2x + 3) > 0\).
Identify the critical points by setting each factor equal to zero: \(x = 0\) and \$2x + 3 = 0 \Rightarrow x = -\frac{3}{2}$.
Use the critical points to divide the real number line into intervals: \((-\infty, -\frac{3}{2})\), \((-\frac{3}{2}, 0)\), and \((0, \infty)\).
Test a value from each interval in the factored inequality \(x(2x + 3) > 0\) to determine where the product is positive, then express the solution set in interval notation.
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Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Polynomial Inequalities
Polynomial inequalities involve expressions where a polynomial is compared to zero or another value using inequality symbols like >, <, ≥, or ≤. Solving them requires finding the values of the variable that make the inequality true, often by analyzing the sign of the polynomial over different intervals.
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Factoring Quadratic Polynomials
Factoring quadratic polynomials means rewriting the expression as a product of two binomials or simpler polynomials. This step is crucial for solving inequalities because it helps identify the roots or zeros, which divide the number line into intervals to test for the inequality.
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Introduction to Factoring Polynomials
Interval Notation and Graphing on the Number Line
Interval notation is a concise way to represent sets of real numbers that satisfy inequalities, using parentheses and brackets to indicate open or closed intervals. Graphing the solution on a number line visually shows where the polynomial inequality holds true, aiding in understanding and verification.
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