Skip to main content
Ch. 1 - Equations and Inequalities
Lial - College Algebra 13th Edition
Lial13th EditionCollege AlgebraISBN: 9780136881063당신이 사용하는 게 아니라요?교과서 변경
2장, 문제 54

Solve each quadratic inequality. Give the solution set in interval notation. x2+4x>-1

검증된 단계별 안내
1
Rewrite the inequality in standard form by moving all terms to one side: \(x^{2} + 4x > -1\) becomes \(x^{2} + 4x + 1 > 0\).
Find the roots of the corresponding quadratic equation \(x^{2} + 4x + 1 = 0\) by using the quadratic formula: \(x = \frac{-b \pm \sqrt{b^{2} - 4ac}}{2a}\), where \(a=1\), \(b=4\), and \(c=1\).
Calculate the discriminant \(\Delta = b^{2} - 4ac\) to determine the nature of the roots and then find the exact roots.
Use the roots to divide the number line into intervals. Test a value from each interval in the inequality \(x^{2} + 4x + 1 > 0\) to determine where the inequality holds true.
Write the solution set in interval notation based on the intervals where the inequality is satisfied.

비슷한 문제에 대한 검증된 영상 답변:

이 영상 해법은 위 문제에 도움이 된다고 튜터들이 추천한 것입니다.
영상 길이:
10m
도움이 되었나요?

주요 개념

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

Quadratic Inequalities

A quadratic inequality involves a quadratic expression set greater than or less than a value, such as x² + 4x > -1. Solving it requires finding the range of x-values that make the inequality true, often by analyzing the related quadratic equation.
추천 영상:
가이드 코스
3:21
Nonlinear Inequalities

Solving Quadratic Equations

To solve a quadratic inequality, first solve the corresponding quadratic equation (e.g., x² + 4x + 1 = 0) to find critical points. These points divide the number line into intervals to test for the inequality's truth.
추천 영상:
06:08
Solving Quadratic Equations by Factoring

Interval Notation and Testing Intervals

After finding critical points, use interval notation to express solution sets. Test values from each interval in the original inequality to determine where it holds true, then write the solution as intervals showing all valid x-values.
추천 영상:
05:18
Interval Notation