Solve each inequality in Exercises 86–91 using a graphing utility. x3 + x2 - 4x - 4 > 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 22
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 − 5x ≤ 0
Verified step by step guidance1
Start by writing the inequality: \$3x^2 - 5x \leq 0$.
Factor the left-hand side expression: factor out the common term \(x\) to get \(x(3x - 5) \leq 0\).
Identify the critical points by setting each factor equal to zero: \(x = 0\) and \$3x - 5 = 0\(, which gives \)x = \frac{5}{3}$.
Determine the sign of the product \(x(3x - 5)\) in the intervals defined by the critical points: \((-\infty, 0)\), \((0, \frac{5}{3})\), and \((\frac{5}{3}, \infty)\).
Use the sign analysis to find where the product is less than or equal to zero, then express the solution set in interval notation and graph it on the real number line.
Verified video answer for a similar problem:This video solution was recommended by our tutors as helpful for the problem above
Video duration:
1mPlay a video:
Was this helpful?
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 (e.g., ≤, ≥, <, >). 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.
Recommended video:
Linear Inequalities
Factoring Quadratic Expressions
Factoring is the process of rewriting a quadratic polynomial as a product of simpler binomials or monomials. For example, 3x² - 5x can be factored as x(3x - 5). Factoring helps identify the roots of the polynomial, which are critical points for determining where the inequality changes sign.
Recommended video:
Solving Quadratic Equations by Factoring
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 is positive, negative, or zero. Together, they help communicate the solution set clearly and precisely.
Recommended video:
Interval Notation
Related Videos
Related Practice
Textbook Question
453
views
