Solve each polynomial inequality. Give the solution set in interval notation. See Examples 2 and 3. (x - 4)(2x + 3)(3x - 1) ≥ 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 39
Textbook Question
Solve each polynomial inequality. Give the solution set in interval notation. See Examples 2 and 3. 2x3 - 7x2 ≥ 3 - 8x
Verified step by step guidance1
First, rewrite the inequality so that all terms are on one side, setting the inequality to be greater than or equal to zero. This means subtracting the right side from both sides: \$2x^3 - 7x^2 - 3 + 8x \geq 0$.
Next, combine like terms to simplify the expression: \$2x^3 - 7x^2 + 8x - 3 \geq 0$.
Now, factor the polynomial expression on the left side if possible. Start by looking for rational roots using the Rational Root Theorem or by trial, then use polynomial division or synthetic division to factor the cubic polynomial into linear and/or quadratic factors.
Once factored, identify the critical points by setting each factor equal to zero and solving for \(x\). These points divide the number line into intervals.
Test a value from each interval in the original inequality to determine whether the inequality holds in that interval. Use this information to write the solution set in interval notation, including endpoints where the inequality is 'greater than or equal to' (≥).
Verified video answer for a similar problem:This video solution was recommended by our tutors as helpful for the problem above
Video duration:
13mPlay 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 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.
Recommended video:
Linear Inequalities
Factoring Polynomials
Factoring is the process of rewriting a polynomial as a product of simpler polynomials or factors. This step is crucial for solving inequalities because it helps identify the roots or zeros of the polynomial, which divide the number line into intervals to test for the inequality.
Recommended video:
Guided course
Introduction to Factoring Polynomials
Interval Notation and Sign Analysis
Interval notation expresses the solution set of inequalities using intervals on the real number line. Sign analysis involves testing values from each interval determined by the roots to see where the polynomial satisfies the inequality, allowing the correct intervals to be included in the solution.
Recommended video:
Interval Notation
Related Videos
Related Practice
Textbook Question
375
views
