Intermediate Algebra: Connecting Concepts through Application

Published by Brooks Cole
ISBN 10: 0-53449-636-9
ISBN 13: 978-0-53449-636-4

Chapter 4 - Quadratic Functions - 4.4 Solving Quadratic Equations by the Square Root Property and Completing the Square - 4.4 Exercises - Page 349: 79

Answer

See graph

Work Step by Step

The function that we want to graph is shown below. Follow the steps outline to graph the function. $$ h(x)=-0.5(x+3)^2+32. $$ Step 1: We first determine the direction in which the function opens. The given function opens downward because the constant $a= -0.5$ is negative. Step 2:Determine the vertex and the equation for the axis of symmetry. The vertex is $(-3,32)$ and the equation for the axis of symmetry is $x = -3$. Step 3: Find the $y$ and $x$ intercepts. To find the $y$ intercept, set $x= 0$ to find the value of $y$. Similarly, to find the $x$ intercept, set $ y= 0$ to find the values of $x$. $$ \begin{aligned} h(0) & =-0.5(0+3)^2+32 \\ & =-0.5(9 )+32 \\ & =27.5 \end{aligned} $$ $y$-intercept: $(0,27.5)$. Set $ y = 0$ and solve. $$ \begin{aligned} -0.5(x+3)^2+32 & =0 \\ (x+3)^2-64 & =0 \\ (x+3)^2 & =64 \\ (x+3)^2 & = \pm \sqrt{64} \\ (x+3) & = \pm 8 \\ x & =-3 \pm 8 \end{aligned} $$Find the two separate solutions: $$ \begin{aligned} x & =-3-8 \\ & =-11 \\ x & =-3+8 \\ & =5 \end{aligned} $$ $x$-intercept: $(-11,0), (5, 0)$. Step 4: Find the domain and range of the function and sketch it. Domain: All real numbers, Range: $(-\infty, 32] $.
Update this answer!

You can help us out by revising, improving and updating this answer.

Update this answer

After you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.