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Ch. 3 - Polynomial and Rational Functions
Blitzer - College Algebra 8th Edition
Blitzer8th EditionCollege AlgebraISBN: 9780136970514당신이 사용하는 게 아니라요?교과서 변경
4장, 문제 11

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

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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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주요 개념

질문에 올바르게 답하기 위해 반드시 이해해야 하는 핵심 개념들은 다음과 같습니다.

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.
추천 영상:
06:07
Linear Inequalities

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.
추천 영상:
가이드 코스
07:30
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.
추천 영상:
05:18
Interval Notation