Chapter 1
A Graphical Approach to Precalculus with Limits · 421 exercises
Problem 39
Write each equation in the form \(y=m x+b .\) (A suggested window for a comprehensive graph of the equation is given. $$\begin{aligned} &-2 x+7 y=4\\\ &[-5,5] \text { by }[-5,5] \end{aligned}$$
4 step solution
Problem 39
Find the slope (if defined) of the line that passes through the given points. $$(-2,1) \text { and }(3,6)$$
5 step solution
Problem 39
find the constant of variation \(k\) and the undetermined value in the table if \(y\) is directly proportional to \(x\). Sales tax \(y\) on a purchase of \(x\) dollars \begin{tabular}{|c|c|c|c|} \hline\(x\) & \(\$ 25\) & 555 & \(?\) \\ \hline\(y\) & \(\$ 1.50\) & \(\$ 3.30\) & \(\$ 5.10\) \end{tabular}
4 step solution
Problem 39
If the \(x\) -coordinate of a point is \(0,\) on which axis must the point lie?
4 step solution
Problem 40
Solve each equation analytically. Check it analytically, and then support the solution graphically. $$-[x-(4 x+2)]=2+(2 x+7)$$
5 step solution
Problem 40
Write each equation in the form \(y=m x+b .\) (A suggested window for a comprehensive graph of the equation is given. $$\begin{aligned} &-0.23 x-0.46 y=0.82\\\ &[-5,5] \text { by }[-5,5] \end{aligned}$$
4 step solution
Problem 40
Find the slope (if defined) of the line that passes through the given points. $$(-2,3) \text { and }(-1,2)$$
4 step solution
Problem 40
If the \(y\) -coordinate of a point is \(0,\) on which axis must the point lie?
4 step solution
Problem 41
Write each equation in the form \(y=m x+b .\) (A suggested window for a comprehensive graph of the equation is given. $$\begin{aligned} &-0.23 x-0.46 y=0.82\\\ &[-5,5] \text { by }[-5,5] \end{aligned}$$$$\begin{aligned} &1.2 x+1.6 y=5.0\\\ &[-6,6] \text { by }[-4,4] \end{aligned}$$
2 step solution
Problem 41
Find the slope (if defined) of the line that passes through the given points. \((8,4)\) and \((-1,-3)\)
3 step solution
Problem 41
Solve each problem. Pressure of a Liquid The pressure exerted by a certain liquid at a given point is directly proportional to the depth of the point beneath the surface of the liquid. If the pressure exerted at 30 feet is 13 pounds per square inch, what is the pressure exerted at 70 feet?
5 step solution
Problem 42
Write each equation in the form \(y=m x+b .\) (A suggested window for a comprehensive graph of the equation is given. $$\begin{aligned} &2 y-5 x=0\\\ &[-10,10] \text { by }[-10,10] \end{aligned}$$
4 step solution
Problem 42
Find the slope (if defined) of the line that passes through the given points. $$(-4,-3) \text { and }(5,0)$$
5 step solution
Problem 42
Solve each problem. Cost of Tuition The cost of tuition is directly proportional to the number of credits taken. If 11 credits cost \(\$ 720.50,\) find the cost of taking 16 credits. What is the constant of variation?
5 step solution
Problem 43
Find the equation of the line described, giving it in slope-intercept form if possible. Through \((-1,4),\) parallel to \(x+3 y=5\)
5 step solution
Problem 43
Find the slope (if defined) of the line that passes through the given points. $$(-11,3) \text { and }(-11,5)$$
4 step solution
Problem 43
Solve each problem. cost of Tuition The cost of tuition is directly proportional to the number of credits taken. If 11 credits cost \(\$ 720.50,\) find the cost of taking 16 credits. What is the constant of variation?
4 step solution
Problem 44
Use the intersection-of-graphs method to approximate each solution to the nearest hundredth. $$9(-0.84 x+\sqrt{17})=\sqrt{6} x-4$$
4 step solution
Problem 44
Find the equation of the line described, giving it in slope-intercept form if possible. Through \((3,-2),\) parallel to \(2 x-y=5\)
4 step solution
Problem 44
Find the slope (if defined) of the line that passes through the given points. $$(-8,2) \text { and }(-8,1)$$
5 step solution
Problem 45
Use the intersection-of-graphs method to approximate each solution to the nearest hundredth. $$2 \pi x+\sqrt[3]{4}=0.5 \pi x-\sqrt{28}$$
5 step solution
Problem 45
Find the equation of the line described, giving it in slope-intercept form if possible. Through \((1,6),\) perpendicular to \(3 x+5 y=1\)
4 step solution
Problem 45
Find the slope (if defined) of the line that passes through the given points. $$\left(\frac{2}{3}, 9\right) \text { and }\left(\frac{1}{2}, 9\right)$$
5 step solution
Problem 46
Find the equation of the line described, giving it in slope-intercept form if possible. Through \((-2,0)\), perpendicular to \(8 x-3 y=7\)
5 step solution
Problem 46
Find the slope (if defined) of the line that passes through the given points. $$(0.12,0.36) \text { and }(0.18,0.36)$$
5 step solution
Problem 46
Solve each problem. Volume of Water \(\mathbf{A}\) water tank in the shape of an inverted cone has height 6 feet and radius 2 feet. If the water level in the tank is 3.5 feet, calculate the volume of the water.
5 step solution
Problem 47
Use the intersection-of-graphs method to approximate each solution to the nearest hundredth. $$0.23(\sqrt{3}+4 x)-0.82(\pi x+2.3)=5$$
6 step solution
Problem 47
Find the equation of the line described, giving it in slope-intercept form if possible. Through \((-5,7)\), perpendicular to \(y=-2\)
4 step solution
Problem 47
Find the slope (if defined) of the line that passes through the given points. $$\left(\frac{1}{2},-\frac{2}{3}\right) \text { and }\left(-\frac{3}{4}, \frac{1}{6}\right)$$
5 step solution
Problem 47
Set the viewing window of your calculator to the given specifications. Make a sketch of your window. $$\begin{aligned} &[-10,10] \text { by }[-10,10]\\\ &\mathrm{Xscl}=1 \quad \mathrm{Yscl}=1 \end{aligned}$$
4 step solution
Problem 48
Use the intersection-of-graphs method to approximate each solution to the nearest hundredth. $$-0.15(6+\sqrt{2} x)+1.4(2 \pi x-6.1)=10$$
4 step solution
Problem 48
Find the equation of the line described, giving it in slope-intercept form if possible. Through \((1,-4),\) perpendicular to \(x=4\)
4 step solution
Problem 48
Solve each problem. Height of a Streethght A person 66 inches tall is standing 15 feet from a streetlight. If the person casts a shadow 84 inches long, how tall is the streetlight?
5 step solution
Problem 48
Set the viewing window of your calculator to the given specifications. Make a sketch of your window. $$\begin{aligned} &[-40,40] \text { by }[-30,30]\\\ &\mathrm{Xscl}=5 \quad \mathrm{Yscl}=5 \end{aligned}$$
5 step solution
Problem 49
Classify each equation as a contradiction, an identity, or a conditional equation. Give the solution set. Use a graph or table to support your answer. $$5 x+5=5(x+3)-3$$
6 step solution
Problem 49
Find the equation of the line described, giving it in slope-intercept form if possible. Through \((-5,8),\) parallel to \(y=-0.2 x+6\)
5 step solution
Problem 49
Solve each problem. Hooke's Law If a 3 -pound weight stretches a spring 2.5 inches, how far will a 17 -pound weight stretch the spring?
5 step solution
Problem 49
Set the viewing window of your calculator to the given specifications. Make a sketch of your window. $$\begin{aligned} &[-6,10] \text { by }[-6,10]\\\ &\mathrm{Xscl}=1 \quad \mathrm{Yscl}=1 \end{aligned}$$
5 step solution
Problem 50
Classify each equation as a contradiction, an identity, or a conditional equation. Give the solution set. Use a graph or table to support your answer. $$5-4 x=5 x-(9+9 x)$$
5 step solution
Problem 50
Find the equation of the line described, giving it in slope-intercept form if possible. Through \((-4,-7),\) parallel to \(x+y=5\)
3 step solution
Problem 50
Solve each problem. Hooke's Law If a 9.8 -pound weight stretches a spring 0.75 inch, how much weight would be needed to stretch the spring 3.1 inches?
5 step solution
Problem 50
Set the viewing window of your calculator to the given specifications. Make a sketch of your window. $$\begin{aligned} &[-3.5,3.5] \text { by }[-4,10]\\\ &\mathrm{Xscl}=1 \quad \mathrm{Yscl}=1 \end{aligned}$$
4 step solution
Problem 51
Find the equation of the line described, giving it in slope-intercept form if possible. Through the origin, perpendicular to \(2 x+y=6\)
5 step solution
Problem 51
Set the viewing window of your calculator to the given specifications. Make a sketch of your window. $$\begin{aligned} &[0,10] \text { by }[0,400]\\\ &\mathrm{Xscl}=1 \quad \mathrm{Yscl}=100 \end{aligned}$$
4 step solution
Problem 52
Classify each equation as a contradiction, an identity, or a conditional equation. Give the solution set. Use a graph or table to support your answer. $$3(x+2)-5(x+2)=-2 x-4$$
5 step solution
Problem 52
If the graph of \(y=m x+b\) falls from left to right and intersects the \(y\) -axis below the origin, then which of the following is true? A. \(m>0, b>0\) B. \(m>0, b<0\) C .\(m<0, b>0\) D. \(m<0, b<0\)
3 step solution
Problem 52
Find the equation of the line described, giving it in slope-intercept form if possible. Through the origin, parallel to \(y=-3.5 x+7.4\)
5 step solution
Problem 52
Solve each problem. Estimating Seal Pups in a Breeding Area According to an actual survey in \(1961,\) to estimate the number of seal pups in a certain breeding area in Alaska, 4963 pups were tagged in early August. In late August, a sample of 900 pups was examined and 218 of these were found to have been tagged. Use this information to estimate, to the nearest hundred, the total number of seal pups in this breeding area.
5 step solution
Problem 52
Set the viewing window of your calculator to the given specifications. Make a sketch of your window. $$\begin{aligned} &[-6.6,6.6] \text { by }[-4.1,4.1]\\\ &\mathrm{Xscl}=1 \quad \mathrm{Yscl}=1 \end{aligned}$$
4 step solution
Problem 53
Classify each equation as a contradiction, an identity, or a conditional equation. Give the solution set. Use a graph or table to support your answer. $$7 x-3[5 x-(5+x)]=1-4 x$$
7 step solution