Table of contents
- 0. Review of Algebra4h 16m
- 1. Equations & Inequalities3h 18m
- 2. Graphs of Equations43m
- 3. Functions2h 17m
- 4. Polynomial Functions1h 44m
- 5. Rational Functions1h 23m
- 6. Exponential & Logarithmic Functions2h 28m
- 7. Systems of Equations & Matrices4h 6m
- 8. Conic Sections2h 23m
- 9. Sequences, Series, & Induction1h 19m
- 10. Combinatorics & Probability1h 45m
1. Equations & Inequalities
Linear Inequalities
Problem 57d
Textbook Question
Solve each rational inequality. Give the solution set in interval notation. See Examples 8 and 9. (x-3)/(x+5)≤0
![](/channels/images/assetPage/verifiedSolution.png)
1
Identify the critical points by setting the numerator and denominator equal to zero: \(x - 3 = 0\) and \(x + 5 = 0\).
Solve these equations to find the critical points: \(x = 3\) and \(x = -5\).
Use these critical points to divide the number line into intervals: \((-\infty, -5)\), \((-5, 3)\), and \((3, \infty)\).
Test a point from each interval in the inequality \(\frac{x-3}{x+5} \leq 0\) to determine where the inequality holds true.
Consider the critical points: check if they satisfy the inequality and include them in the solution set if they do. Finally, express the solution set in interval notation.
Recommended similar problem, with video answer:
![](/channels/images/assetPage/verifiedSolution.png)
This video solution was recommended by our tutors as helpful for the problem above
Video duration:
6mPlay a video:
Was this helpful?
Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Rational Inequalities
Rational inequalities involve expressions that are ratios of polynomials set in relation to an inequality (e.g., ≤, ≥). To solve them, one must determine where the rational expression is positive, negative, or zero. This often requires finding critical points where the numerator or denominator equals zero and testing intervals around these points.
Recommended video:
Guided course
Rationalizing Denominators
Interval Notation
Interval notation is a mathematical notation used to represent a range of values. It uses parentheses and brackets to indicate whether endpoints are included (closed interval) or excluded (open interval). For example, (a, b) means all numbers between a and b, not including a and b, while [a, b] includes both endpoints.
Recommended video:
Interval Notation
Critical Points
Critical points are values of the variable where the rational expression is either zero or undefined. For the inequality (x-3)/(x+5)≤0, the critical points are found by setting the numerator (x-3) to zero and the denominator (x+5) to zero. These points help to divide the number line into intervals for testing the sign of the rational expression.
Recommended video:
Guided course
Point-Slope Form
Related Videos
Related Practice