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College Algebra
Functions and Graphs

1
The Coordinate System; Lines and Their Graphs

Problem 1

Find the slope of the line passing through the points \((-1,2)\) and \((-3,4)\). Plot the points and indicate the slope on your plot.

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Mr. Hampton cc
Mr. Hampton
Lauren cc
Lauren
Gordon cc
Gordon
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Julieta
Problem 2

Find the equation of the line passing through \((2,6)\) and \((-1,-2)\) in point-slope form.

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Mr. Hampton cc
Mr. Hampton
Lauren cc
Lauren
Gordon cc
Gordon
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Octabio
Problem 3

Write the equation of a line with a slope of \(-4\) and \(y\)-intercept of \((0,\sqrt{2})\) in slope-intercept form. Does \((0,1)\) lie on this line? Find the \(x\)-intercept of this line.

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Mr. Hampton cc
Mr. Hampton
Lauren cc
Lauren
Gordon cc
Gordon
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Julieta
Problem 4

Find the equation, in slope-intercept form, of the line whose graph is given in Figure 7.

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Mr. Hampton cc
Mr. Hampton
Breylor cc
Breylor
Julieta cc spanish language icon
Julieta
Problem 5

Find the equations of the lines described below.

  1. A horizontal line passing through the point \((2,3)\).

  2. A vertical line passing through the point \((1,-2)\)

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Mr. Hampton cc
Mr. Hampton
Lauren cc
Lauren
Gordon cc
Gordon
Julieta cc spanish language icon
Julieta
Problem 6

Write the equation \(3x+2y-4=0\) in slope-intercept form and graph the line.

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Mr. Hampton cc
Mr. Hampton
Lauren cc
Lauren
Breylor cc
Breylor
Octabio cc spanish language icon
Octabio
Problem 7

Find the equation of the line parallel to \(2x-y=1\) and passing though \((2,-3)\). Write the equation in slope-intercept form.

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Lauren cc
Lauren
Gordon cc
Gordon
Nathan cc
Nathan
Breylor cc
Breylor
Problem 8

Find an equation of the line perpendicular to \(2x+3y-1=0\) and passing through \((4,-1)\). Write the equation in slope-intercept form.

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Mr. Hampton cc
Mr. Hampton
Lauren cc
Lauren
Gordon cc
Gordon
Julieta cc spanish language icon
Julieta
Problem 9

A 2012 Honda Civics value over time can be approximated by the equation \(v=-2200t+22000\) where \(t\) denotes the number of years after its purchase. Answer the following questions:

  1. What will be the value of the car \(6\) years after purchase.

  2. What are the slope and \(v\)-intercept, and what do they represent?

  3. For what value of \(t\) will the value of the car be zero?

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Mr. Hampton cc
Mr. Hampton
Lauren cc
Lauren
Gordon cc
Gordon
Julieta cc spanish language icon
Julieta
Problem 10

In 2010, there were \(1\text{,}400\) Canada Geese in a wildfire refuge. In 2016, their population increased to \(1\text{,}820\).

  1. Write an equation for the population of Canada Geese, \(y\), in terms of \(x\), the number of years since 2010.

  2. What are the slope and \(y\)-intercept and what do they represent?

  3. When will the goose population reach \(1\text{,}960\)?

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Mr. Hampton cc
Mr. Hampton
Lauren cc
Lauren
Gordon cc
Gordon
Octabio cc spanish language icon
Octabio

2
Coordinate Geometry, Circles, and Other Equations

Problem 1
  1. Find the distance between the points \((3,-5)\) and \((6,1)\).

  2. Find the midpoint of the line segment joining the points \((3,-5)\) and \((6,1)\).

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Mr. Hampton cc
Mr. Hampton
Lauren cc
Lauren
Gordon cc
Gordon
Julieta cc spanish language icon
Julieta
Problem 2

Write the standard form of the equation of the circle with a center at \((3,-2)\) and radius \(5\). Sketch the circle.

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Mr. Hampton cc
Mr. Hampton
Lauren cc
Lauren
Gordon cc
Gordon
Octabio cc spanish language icon
Octabio
Problem 3

Write the standard form of the equation of the circle with center at \((-1,2)\) and containing the point \((1,5)\). Sketch the circle.

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Mr. Hampton cc
Mr. Hampton
Lauren cc
Lauren
Gordon cc
Gordon
Julieta cc spanish language icon
Julieta
Problem 4

Write the equation of the circle, \(x^2+y^2+8x-2y-8=0\), in standard form. Find the coordinates of the center of the circle and find its radius. Sketch the circle.

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Mr. Hampton cc
Mr. Hampton
Lauren cc
Lauren
Breylor cc
Breylor
Julieta cc spanish language icon
Julieta
Problem 5

sketch the graph of the equation \(y-x^2=-3\)

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Mr. Hampton cc
Mr. Hampton
Lauren cc
Lauren
Gordon cc
Gordon
Julieta cc spanish language icon
Julieta
Problem 6

Sketch the graph of the equation \(y^2+x=0\)

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Mr. Hampton cc
Mr. Hampton
Lauren cc
Lauren
Gordon cc
Gordon
Octabio cc spanish language icon
Octabio

3
Functions

Problem 1

Which of the following correspondences satisfy the definition of a function?

  1. The input value is one of the letters from the set \(\{\text{J, F, M, A, S, O, N, D}\}\) and the output value is a name of a month beginning with that letter.

  2. The correspondence defined by Table 1.

  3. The input value is the radius of a circle and the output value is the area of the circle.

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Mr. Hampton cc
Mr. Hampton
Lauren cc
Lauren
Breylor cc
Breylor
Julieta cc spanish language icon
Julieta
Problem 2

Let \(f(x)=x^2-1\). Evaluate the following.

  1. \(f(-2)\)

  2. \(f\left(\dfrac{1}{2}\right)\)

  3. \(f(x+1)\)

  4. \(f\left(\sqrt{5}\right)\)

  5. \(f(x^3)\)

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Mr. Hampton cc
Mr. Hampton
Lauren cc
Lauren
Gordon cc
Gordon
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Julieta
Problem 3

Evaluate \(g(-3)\) and \(g\left(a^2\right)\) for the following functions.

  1. \(g(x)=\dfrac{\sqrt{1-x}}{2}\)

  2. \(g(x)=\dfrac{x+4}{x-2}\)

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Lauren cc
Lauren
Breylor cc
Breylor
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Octabio
Problem 4

Define \(H(x)\) as follows: \[H(x)= \begin{cases} 1 & \text{if } x < 0; \\ -x+1 & \text{if } 0 < x \leq 2; \\ -3 & \text{if } x > 2. \end{cases}\] Evaluate the following, if defined:

  1. \(H(2)\)

  2. \(H(-6)\)

  3. \(H(0)\)

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Mr. Hampton cc
Mr. Hampton
Lauren cc
Lauren
Gordon cc
Gordon
Julieta cc spanish language icon
Julieta
Problem 5

Find the domain of each of the following functions. Write your answer using interval notation.

  1. \(g(t)=t^2+4\)

  2. \(f(x)=\sqrt{4-x}\)

  3. \(h(s)=\dfrac{1}{s-1}\)

  4. \(h(t)=\dfrac{1}{\sqrt{4-t}}\)

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Saba cc
Saba
Lauren cc
Lauren
Gordon cc
Gordon
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Julieta
Problem 6

Eduardo is a part-time salesperson at Digitex Audio, a sound equipment store. Each week, he is paid a salary of \(\$200\) plus a commission of \(10\%\) of the amount of sales he generates that week, in dollars.

  1. What are the input and output variables for this problem?

  2. Express Eduardo’s pay for one week as a function of the sales he generates that week.

  3. What was his pay for a week in which he generated \(\$4000\) worth of sales?

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Mr. Hampton cc
Mr. Hampton
Lauren cc
Lauren
Gordon cc
Gordon
Julieta cc spanish language icon
Julieta
Problem 7

Table 3 gives the U.S. Postal Service’s rate for a first-class letter in 2013 as a function of the weight of the letter. Letters heavier than \(3.5\) ounces are classified separately, and are not listed here.

  1. Identify the independent variable and the dependent variable.

  2. Explain why this table represents a function.

  3. What is the rate for a first-class letter weighing \(3.2\) ounces?

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Mr. Hampton cc
Mr. Hampton
Lauren cc
Lauren
Octabio cc spanish language icon
Octabio
Problem 8

Figure 4 depicts the average high temperature in Fargo, North Dakota, in degrees Fahrenheit, as a function of the month of the year.

  1. Let \(T(m)\) be the function by the graph, where \(m\) is the month of the year. What is \(T(\text{May})\)?

  2. What are the valid input values for this function?

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Mr. Hampton cc
Mr. Hampton
Lauren cc
Lauren
Julieta cc
Julieta
Julieta cc spanish language icon
Julieta

4
Graphs of Functions

Problem 1

Does the following set of points define s function?
\(S=\{(-1,-1), (0,0), (1,2), (2,4)\}\)

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Mr. Hampton cc
Mr. Hampton
Lauren cc
Lauren
Julieta cc spanish language icon
Julieta
Problem 2

Graph the function \(f(x)=\dfrac{2}{3}x-2\)

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Mr. Hampton cc
Mr. Hampton
Lauren cc
Lauren
Breylor cc
Breylor
Julieta cc spanish language icon
Julieta
Problem 3

Graph the function \(g(t)=-2t^2\). Use the graph to find the domain and range of \(g\).

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Lauren cc
Lauren
Breylor cc
Breylor
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Julieta
Problem 4

Graph each of the following functions. Use the graph to find the domain and range of \(f\).

  1. \(f(x)=\sqrt{4-x}\)

  2. \(f(x)=\lvert x\rvert\)

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Mr. Hampton cc
Mr. Hampton
Lauren cc
Lauren
Breylor cc
Breylor
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Julieta
Problem 5

Graph the function \(H(x)\), defined as follows: \[H(x)= \begin{cases} x^2 & \text{if } x < 0; \\ x+1 & \text{if } 0 \leq x < 3; \\ -1 & \text{if } x \geq 2. \end{cases}\]

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Lauren cc
Lauren
Breylor cc
Breylor
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Julieta
Problem 6

Use the vertical line test to determine which of the graphs in Figure 15 are graphs of functions.

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Mr. Hampton cc
Mr. Hampton
Lauren cc
Lauren
Breylor cc
Breylor
Julieta cc spanish language icon
Julieta
Problem 7

Consider the graph of the function \(f\) shown in Figure 17.

  1. Find \(f(-1)\), \(f(0)\), and \(f(2)\).

  2. Find the domain of \(f\).

  3. What are the \(x\)- and \(y\)-intercepts of the graph of \(f\)?

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Mr. Hampton cc
Mr. Hampton
Lauren cc
Lauren
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Julieta
Problem 8

Which of the following equations describes \(y\) as a function of \(x\)?

  1. \(2x-y=1\)

  2. \(\lvert y\rvert =x\)

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Mr. Hampton cc
Mr. Hampton
Lauren cc
Lauren
Breylor cc
Breylor
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Julieta

5
Linear Functions and Models; Regression; Variation

Problem 1

At the end of the year, Jocelyn’s employer gives her an annual bonus of \(\$1000\) plus \(\$200\) for each year she has been employed by the company. Answer the following questions.

  1. Find a linear function that relates Jocelyn’s bonus to the number of years of her employment with the company.

  2. Use the function you found in part (a) to calculate the annual bonus Jocelyn will receive after she has worked for the company for \(8\) years,

  3. Use the function you found in part (a) to calculate how long Jocelyn would have to work at the company for her annual bonus to amount to \(\$3200\).

  4. Interpret the slope and \(y\)-intercept for this problem both verbally and graphically.

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Mr. Hampton cc
Mr. Hampton
Shelby cc
Shelby
Breylor cc
Breylor
Julieta cc spanish language icon
Julieta
Problem 2

The volume if a fixed mass of gas is directly proportional to its temperature, measured in degrees Kelvin. If the volume of a gas is \(450\) cc (cubic centimeters) at \(300\) K (degrees Kelvin), find the following:

  1. The variation constant \(k\) in the equation \(V=kT\).

  2. The volume of the gas at \(340\) K.

  3. The temperature of the same gas if the volume is \(300\) cc.

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Julieta cc
Julieta
Julieta cc spanish language icon
Julieta
Problem 3

The price of a product is inversely proportional to its demand. That is, \(P=\dfrac{k}{p}\), where \(P\) is the price per unit and \(q\) is the number of products demanded. If \(3000\) units are demanded at \(\$10\) per unit, how many units are demanded at \(\$6\) per unit?

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Shelby cc
Shelby
Breylor cc
Breylor
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Julieta

6
Analyzing the Graph of a Function; Rate of Change; Difference Quotients

Problem 1

Using the definitions of odd and even functions, classify the following functions as odd, even, or neither.

  1. \(f(x)=\lvert x\rvert +2\)

  2. \(g(x)=(x-4)^2\)

  3. \(h(x)=-x^3+3x\)

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Mr. Hampton cc
Mr. Hampton
Lauren cc
Lauren
Breylor cc
Breylor
Julieta cc spanish language icon
Julieta
Problem 2

For the function \(f\) given in Figure 10, find the interval(s) on which

  1. \(f\) is increasing

  2. \(f\) is decreasing

  3. \(f\) is constant

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Mr. Hampton cc
Mr. Hampton
Lauren cc
Lauren
Breylor cc
Breylor
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Julieta
Problem 3

Find the average rate of change of \(f(x)=2x^2+1\) on the following intervals:

  1. \([-3,-2]\)

  2. \([0,2]\)

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Mr. Hampton cc
Mr. Hampton
Lauren cc
Lauren
Breylor cc
Breylor
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Julieta
Problem 4

A ball is dropped from a height of \(100\) meters. At time \(t\), in seconds, the height of the ball from the ground is given by \(f(t)=-4.9t^2+100\). Calculate the following:

  1. The average rate of change of \(f\) on the interval \([1,3]\).

  2. The difference quotient \(\dfrac{f(a+h)-f(a)}{h}\)

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Mr. Hampton cc
Mr. Hampton
Lauren cc
Lauren
Breylor cc
Breylor
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Julieta

7
The Algebra of Functions

Problem 1

Let \(f\) and \(g\) be two functions defined as follows:
\(f(x)=\dfrac{2}{x-4}\) and \(g(x)=3x-1\)
Find the following and determine the domain of each.

  1. \((f+g)(x)\)

  2. \((f-g)(x)\)

  3. \((fg)(x)\)

  4. \(\left(\dfrac{f}{g}\right)(x)\)

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Saba cc
Saba
Lauren cc
Lauren
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Julieta
Problem 2

Let \(f\) and \(g\) be two functions defined as follows:
\(f(x)=2x^2-x\) and \(g(x)=\sqrt{x+1}\)
Find the following and determine the domain of each.

  1. \((f+g)(-1)\)

  2. \(\left(\dfrac{f}{g}\right)(3)\)

  3. \((fg)(3)\)

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Mr. Hampton cc
Mr. Hampton
Lauren cc
Lauren
Octabio cc spanish language icon
Octabio
Problem 3

The GlobalEx Corporation has revenues modeled by the function \(R(t)=40+2t\), where \(t\) is the number of years since 2010 and \(R(t)\) is in millions of dollars. Its operating costs are modeled by the function \(C(t)=35+1.6t\), where \(t\) is the number of years since 2010 and \(C(t)\) is in millions of dollars. Find the profit function \(P(t)\) for GlobalEx Corporation.

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Mr. Hampton cc
Mr. Hampton
Lauren cc
Lauren
Nathan cc
Nathan
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Julieta
Problem 4

Let \(f(s)=s^2+1\) and \(g(s)=-2s\).

  1. Find an expression for \((f\circ g)(s)\) and give the domain of \(f\circ g\).

  2. Find an expression for \((g\circ f)(s)\) and give the domain of \(g\circ f\).

  3. Evaluate \((f\circ g)(-1)\).

  4. Evaluate \((g\circ f)(-1)\)

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Mr. Hampton cc
Mr. Hampton
Lauren cc
Lauren
Nathan cc
Nathan
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Julieta
Problem 5

Let \(f(x)=\dfrac{1}{x}\) and \(g(x)=x^2-1\).

  1. Find \(f\circ g\) and its domain.

  2. Find \(g\circ f\) and its domain.

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Mr. Hampton cc
Mr. Hampton
Lauren cc
Lauren
Nathan cc
Nathan
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Julieta
Problem 6

If \(h(x)=\sqrt{3x^2-1}\), find two functions \(f\) and \(g\) such that \(h(x)=(f\circ g)(x)=f(g(x))\).

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Mr. Hampton cc
Mr. Hampton
Lauren cc
Lauren
Breylor cc
Breylor
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Octabio
Problem 7

The cost of fuel for running a fleet of vehicles owned by GlobalEx Corporation is given by \(C(x)=2.5x\), where \(x\) is the total number of gallons of fuel used. The Canadian branch, however, records its fuel consumption in liters. The conversion from liters to gallons is given by the function \(G(x)=0.26x\), where \(x\) is the number of liters.

  1. Find \((C\circ G)(x)\) and interpret it.

  2. Find the cost for \(120\) liters of fuel, reported by the Canadian branch.

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Julieta cc
Julieta
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Julieta
Problem 8

Compute \(\dfrac{f(x+h)-f(x)}{h}\), \(h\neq 0\), for \(f(x)=2x^2+1\).

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Mr. Hampton cc
Mr. Hampton
Lauren cc
Lauren
Breylor cc
Breylor
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Julieta

8
Transformations of the Graph of a Function

Problem 1

Make a table of values of the functions \(f(x)=\lvert x \rvert\) and \(g(x)=\lvert x \rvert -2\), for \(x=-3\), \(-2\), \(-1\), \(0\), \(1\), \(2\), \(3\). Use your table to sketch the graphs of the two functions. What are the domain and range of \(f\) and \(g\)?

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Mr. Hampton cc
Mr. Hampton
Lauren cc
Lauren
Breylor cc
Breylor
Julieta cc spanish language icon
Julieta
Problem 2

Make a table of values of the functions \(f(x)=\lvert x \rvert\) and \(g(x)=\lvert x-2 \rvert\), for \(x=-3\), \(-2\), \(-1\), \(0\), \(1\), \(2\), \(3\). Use your table to sketch the graphs of the two functions. What are the domain and range of \(f\) and \(g\)?

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Mr. Hampton cc
Mr. Hampton
Lauren cc
Lauren
Nathan cc
Nathan
Octabio cc spanish language icon
Octabio
Problem 3

Use vertical and/or horizontal shifts, along with a table of values, to graph the following functions:

  1. \(g(x)=\sqrt{x+2}\)

  2. \(g(x)=\lvert x+3 \rvert -2\)

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Mr. Hampton cc
Mr. Hampton
Lauren cc
Lauren
Nathan cc
Nathan
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Julieta
Problem 4

Identify the basic function \(f(x)\) which is transformed to obtain \(g(x)\). Then use transformations to sketch the graphs of both \(f(x)\) and \(g(x)\).

  1. \(g(x)=3\sqrt{x}\)

  2. \(g(x)=-2\lvert x \rvert\)

  3. \(g(x)=-2\lvert x+1 \rvert +3\)

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Mr. Hampton cc
Mr. Hampton
Lauren cc
Lauren
Nathan cc
Nathan
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Julieta
Problem 5

Suppose the graph of a function \(g(x)\) is produced from the graph of \(f(x)=x^2\) by vertically compressing the graph of \(f\) by a factor of \(\dfrac{1}{3}\), then shifting it to the left by \(1\) unit, and finally shifting it downward by \(2\) units. Give an expression for \(g(x)\) and sketch the graphs of both \(f\) and \(g\).

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Mr. Hampton cc
Mr. Hampton
Lauren cc
Lauren
Nathan cc
Nathan
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Julieta
Problem 6

The graph of \(f(x)\) is shown in Figure 20. Use it to sketch the graphs of

  1. \(f(3x)\)

  2. \(f(-x)+1\)

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Mr. Hampton cc
Mr. Hampton
Lauren cc
Lauren
Nathan cc
Nathan
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Octabio