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. (x+3)(x−5)>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 11
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. 3x2+10x−8≤0
Verified step by step guidance1
Start by writing down the inequality: \$3x^{2} + 10x - 8 \leq 0$.
To solve the inequality, first find the roots of the corresponding quadratic equation \$3x^{2} + 10x - 8 = 0\( by using the quadratic formula: \)x = \frac{-b \pm \sqrt{b^{2} - 4ac}}{2a}\(, where \)a=3\(, \)b=10\(, and \)c=-8$.
Calculate the discriminant \(\Delta = b^{2} - 4ac = 10^{2} - 4 \times 3 \times (-8)\) to determine the nature of the roots.
Find the two roots by substituting the values into the quadratic formula. These roots will divide the real number line into intervals.
Test a value from each interval in the original inequality \$3x^{2} + 10x - 8 \leq 0$ to determine which intervals satisfy the inequality, then express the solution set in interval notation and graph it on the real number line.
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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 (>, <, ≥, ≤). 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 is the process of rewriting a quadratic polynomial as a product of two binomials. This helps identify the roots (zeros) of the polynomial, which are critical points for determining where the polynomial changes sign in inequalities.
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Introduction to Factoring Polynomials
Interval Notation and Number Line Graphing
Interval notation is a concise way to represent sets of real numbers, especially solution sets of inequalities. Graphing on a number line visually shows where the polynomial satisfies the inequality, using open or closed dots to indicate whether endpoints are included.
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