/*! 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 48 Find the zeros of \(f(x)=x^{2}+6... [FREE SOLUTION] | 91Ó°ÊÓ

91Ó°ÊÓ

Find the zeros of \(f(x)=x^{2}+6 x-8\)

Short Answer

Expert verified
The zeros are \(x = -8\) and \(x = 2\).

Step by step solution

01

Identify the quadratic equation

The given function is a quadratic equation in the standard form: \[f(x) = x^2 + 6x - 8\]We need to find the values of \(x\) for which the function equals zero, i.e., \(f(x) = 0\).
02

Set the equation to zero

Set the quadratic function equal to zero:\[x^2 + 6x - 8 = 0\]
03

Factor the quadratic equation

To solve the equation by factoring, find two numbers that multiply to -8 and add to 6. The numbers 8 and -2 work because:\[8 \times (-2) = -8\]\[8 + (-2) = 6\]So, we can factor the quadratic as:\[x^2 + 6x - 8 = (x + 8)(x - 2)\]
04

Solve for the zeros

Set each factor equal to zero and solve for \(x\):\[x + 8 = 0 \rightarrow x = -8\]\[x - 2 = 0 \rightarrow x = 2\]

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with 91Ó°ÊÓ!

Key Concepts

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

Factoring Quadratics
Factoring quadratics means expressing the quadratic equation in the form of a product of its linear factors. Given the quadratic equation \(x^2 + 6x - 8\), we aim to rewrite it as a product of two binomials.

To do this, we look for two numbers that multiply to the constant term (in this case, -8) and add up to the coefficient of the linear term (here, 6).

In the equation \(x^2 + 6x - 8\), the two numbers that work are 8 and -2 because 8 \( \times \) -2 = -8 and 8 + (-2) = 6. This gives us the factors (x + 8) and (x - 2).

Therefore, we can write: \[x^2 + 6x - 8 = (x + 8)(x - 2)\]

Factoring is crucial because it simplifies the process of finding solutions to the quadratic equation.
Finding Zeros
Finding the zeros of a quadratic function means determining the values of \x\ where the function equals zero. For the given function \(f(x)=x^2 + 6x - 8\), we are interested in the values of \x\ that make \f(x) = 0\.

After factoring the quadratic equation \(x^2 + 6x - 8\) into \((x + 8)(x - 2)\), we set each factor equal to zero. This step is based on the Zero Product Property, which states that if the product of two numbers is zero, at least one of the numbers must be zero.

Setting each factor to zero will look like this:
  • \x + 8 = 0 \rightarrow x = -8\
  • x - 2 = 0 \rightarrow x = 2 \
This results in the solutions \x = -8\ and \x = 2\, which are the zeros of the function. This means that the function \(f(x)\) crosses the x-axis at these points.
Solving Quadratic Equations
Solving a quadratic equation involves finding the values of \x\ that make the equation true. For the quadratic equation \(x^2 + 6x - 8 = 0 \), we have already factored it to get \((x + 8)(x - 2) = 0\).

The next steps involved using the factors to find the solutions by setting each factor equal to zero:
\[x + 8 = 0 \rightarrow x = -8\]
\[x - 2 = 0 \rightarrow x = 2\]

Thus, the solutions to the quadratic equation \(x^2 + 6x - 8 = 0\) are \x = -8\ and \x = 2\. These solutions are where the graph of the quadratic function intersects the x-axis.

It's important to recognize that solving quadratic equations can be approached in different ways, such as factoring, using the quadratic formula, or completing the square. In this problem, factoring was the best method because the quadratic easily factored into two linear binomials.

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

The marginal cost \(C\) (in dollars) of manufacturing \(x\) smartphones (in thousands) is given by $$ C(x)=5 x^{2}-200 x+4000 $$ (a) How many smartphones should be manufactured to minimize the marginal cost? (b) What is the minimum marginal cost?

In Problems 50 and 51 , if \(f(x)=x^{2}+2 x-7\) and \(g(x)=3 x-4\) find: 51\. \((f \cdot g)(x)\)

53\. Simplify: \(\frac{5 x^{4}(2 x+7)^{4}-8 x^{5}(2 x+7)^{3}}{(2 x+7)^{8}}\)

Artillery A projectile fired from the point (0,0) at an angle to the positive \(x\) -axis has a trajectory given by $$ y=c x-\left(1+c^{2}\right)\left(\frac{g}{2}\right)\left(\frac{x}{v}\right)^{2} $$ where \(x=\) horizontal distance in meters \(y=\) height in meters \(\begin{aligned} v=& \text { initial muzle velocity in meters per second (m/s) } \\ g=& \text { acceleration due to gravity }=9.81 \text { meters per second } \\ & \text { squared (m/s }^{2} \text { ) } \end{aligned}\) \(c>0\) is a constant determined by the angle of elevation. A howitzer fires an artillery round with a muzzle velocity of \(897 \mathrm{~m} / \mathrm{s}\) (a) If the round must clear a hill 200 meters high at a distance of 2000 meters in front of the howitzer, what \(c\) values are permitted in the trajectory equation? (b) If the goal in part (a) is to hit a target on the ground 75 kilometers away, is it possible to do so? If so, for what values of \(c ?\) If not, what is the maximum distance the round will travel? Source: wwianswers.com

Are based on material learned earlier in the course. The purpose of these problems is to keep the material fresh in your mind so that you are better prepared for the final exam. Suppose \(f(x)=x^{2}-3 x+7\). Find an equation of the secant line containing the points \((-1, f(-1))\) and \((2, f(2))\)

See all solutions

Recommended explanations on Math Textbooks

View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.