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Ch. 3 - Polynomial and Rational Functions
Blitzer - College Algebra 8th Edition
Blitzer8th EditionCollege AlgebraISBN: 9780136970514Non è quello che usi tu?Cambia libro di testo
Capitolo 4, Problema 72

In Exercises 71–72, use the graph of the polynomial function to solve each inequality.


2x3 + 11x2 < 7x + 6
Graph of the polynomial function f(x) = 2x^3 + 11x^2 - 7x - 6.

Guida verificata passo dopo passo
1
Rewrite the given inequality \(2x^{3} + 11x^{2} < 7x + 6\) by bringing all terms to one side to set the inequality to zero: \(2x^{3} + 11x^{2} - 7x - 6 < 0\).
Recognize that the left side of the inequality is the polynomial function \(f(x) = 2x^{3} + 11x^{2} - 7x - 6\) whose graph is provided.
Identify the x-intercepts (roots) of the polynomial from the graph, which are approximately at \(x = -7\), \(x = -3\), and \(x = 1\). These points divide the x-axis into intervals.
Determine the sign of \(f(x)\) on each interval by observing whether the graph is above or below the x-axis: where the graph is below the x-axis, \(f(x) < 0\); where it is above, \(f(x) > 0\).
Write the solution to the inequality \(f(x) < 0\) as the union of intervals where the graph lies below the x-axis, using the roots as boundaries.

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