/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Problem 28 Solve each quadratic inequality ... [FREE SOLUTION] | 91Ó°ÊÓ

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Solve each quadratic inequality by locating the \(x\) -intercept(s) (if they exist), and noting the end behavior of the graph. Begin by writing the inequality in function form as needed. $$-x^{2}+3 x<3$$

Short Answer

Expert verified
The inequality is true for all real x.

Step by step solution

01

Write in Function Form

The first step is to write the inequality \(-x^{2}+3x<3\) in function form. We need to rearrange it to look like a quadratic function by bringing all the terms to one side of the inequality.Subtract 3 from both sides:\[-x^2 + 3x - 3 < 0\]
02

Identify as Quadratic Function

Recognize the left-hand side as a quadratic function, i.e., \(f(x) = -x^2 + 3x - 3\).We'll now study this quadratic to solve the inequality.
03

Solve the Equation for x-intercepts

To find the x-intercepts, solve the equation \(-x^2 + 3x - 3 = 0\).Rearrange into standard quadratic form: \(x^2 - 3x + 3 = 0\).Use the quadratic formula \(x = \frac{-b \pm \sqrt{b^2-4ac}}{2a}\) where \(a = 1\), \(b = -3\), \(c = 3\).\[ x = \frac{-(-3) \pm \sqrt{(-3)^2-4(1)(3)}}{2(1)} \]\[ x = \frac{3 \pm \sqrt{9-12}}{2} \]\[ x = \frac{3 \pm \sqrt{-3}}{2} \]The discriminant is negative, meaning there are no real x-intercepts.
04

Analyze End Behavior

Examine the end behavior of the quadratic function \(f(x) = -x^2 + 3x - 3\).Since the leading coefficient \(-1\) is negative, the parabola opens downwards. As \(x\) approaches infinity or negative infinity, \(f(x)\) approaches negative infinity.
05

Conclusion Based on Analysis

The function \(f(x)\) is a downward-opening parabola without real x-intercepts, which means it's always below the x-axis.Therefore, \(-x^2 + 3x - 3 < 0\) is satisfied for all real values of \(x\).

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Key Concepts

These are the key concepts you need to understand to accurately answer the question.

x-intercepts
Finding the x-intercepts of a quadratic function means identifying when the output, or f(x), is zero. These intercepts are the points where the parabola crosses the x-axis. In the equation \(-x^{2} + 3x - 3 = 0\), we rearrange it into the standard form \(x^{2} - 3x + 3 = 0\) and try to find solutions using the quadratic formula.

However, if the discriminant (the expression under the square root in the quadratic formula) is negative, there are no real solutions, meaning the function does not cross the x-axis. In our case, the discriminant is \(-3\), confirming no real x-intercepts exist for our function. This tells us that the parabola stays entirely above or below the x-axis.
end behavior
The end behavior of a quadratic function informs us how the function behaves as the input variable, x, moves towards positive or negative infinity. By observing the leading term of the quadratic function, specifically its coefficient and sign, we can determine this behavior.

In the quadratic function \(f(x) = -x^{2} + 3x - 3\), the leading term is \(-x^{2}\). With a negative leading coefficient, the parabola opens downward. This means that both ends of the parabola will approach negative infinity as x moves towards positive or negative infinity.
  • If the leading coefficient is positive, the parabola opens upwards, heading towards positive infinity.
  • If it’s negative, like in our function, the ends drop down toward negative infinity.
Understanding end behavior helps predict the graph's direction based solely on the quadratic's leading term.
parabola
A parabola is a U-shaped plot that represents a quadratic function visually. It can open upwards or downwards based on the leading coefficient of the quadratic term. The vertex forms the parabola's peak if it opens downward, or its lowest point if it opens upward.

For our quadratic function \(f(x) = -x^{2} + 3x - 3\), the leading coefficient is \(-1\), indicating that the parabola opens downwards. This down opening shape confirms that as x values increase or decrease, the function value f(x) drops below the x-axis.
  • When no real x-intercepts are present, the entire parabola can either sit above or fall below the x-axis, depending on the direction it opens.
Understanding the orientation of a parabola helps in predicting its positioning relative to the x-axis and solving inequalities involving quadratic functions.
quadratic function
A quadratic function is any function in the standard form \(ax^{2} + bx + c\), where a, b, and c are constants, and a is not zero. These functions create parabolic graphs and can model various real-world scenarios due to their distinctive U-shape.

Given the function \(f(x) = -x^{2} + 3x - 3\), we identify it as quadratic because its highest degree term is \(x^{2}\). The leading term here (\

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Most popular questions from this chapter

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