Chapter 1
Precalculus Essentials · 780 exercises
Problem 133
Determine whether each statement makes sense or does not make sense, and explain your reasoning. My graph is decreasing on \((-\infty, a)\) and increasing on \((a, \infty)\) so \(f(a)\) must be a relative maximum.
4 step solution
Problem 133
Use point plotting to graph \(f(x)=x+2\) if \(x \leq 1\)
5 step solution
Problem 133
What must be done to a function's equation so that its graph is stretched vertically?
3 step solution
Problem 134
Simplify: \(2(x+h)^{2}+3(x+h)+5-\left(2 x^{2}+3 x+5\right)\)
4 step solution
Problem 134
What must be done to a function's equation so that its graph is shrunk horizontally?
3 step solution
Problem 135
I graphed $$f(x)=\left\\{\begin{array}{lll} 2 & \text { if } & x \neq 4 \\ 3 & \text { if } & x=4 \end{array}\right.$$ and one piece of my graph is a single point.
3 step solution
Problem 135
a. Use a graphing utility to graph \(f(x)=x^{2}+1\) b. Graph \(f(x)=x^{2}+1, g(x)=f(2 x), h(x)=f(3 x),\) and \(k(x)=f(4 x)\) in the same viewing rectangle. c. Describe the relationship among the graphs of \(f, g, h\) and \(k,\) with emphasis on different values of \(x\) for points on all four graphs that give the same \(y\) -coordinate. d. Generalize by describing the relationship between the graph of \(f\) and the graph of \(g,\) where \(g(x)=f(c x)\) for \(c>1\) e. Try out your generalization by sketching the graphs of \(f(c x)\) for \(c=1, c=2, c=3,\) and \(c=4\) for a function of your choice.
5 step solution
Problem 136
I noticed that the difference quotient is always zero if \(f(x)=c,\) where \(c\) is any constant.
3 step solution
Problem 136
a. Use a graphing utility to graph \(f(x)=x^{2}+1\)
b. Graph \(f(x)=x^{2}+1, g(x)=f\left(\frac{1}{2} x\right),\) and
\(h(x)=f\left(\frac{1}{4} x\right)\)
in the same viewing rectangle.
c. Describe the relationship among the graphs of \(f, g,\) and \(h,\) with
emphasis on different values of \(x\) for points on all three graphs that give
the same \(y\) -coordinate.
d. Generalize by describing the relationship between the graph of \(f\) and the
graph of \(g,\) where \(g(x)=f(c x)\) for \(0
6 step solution
Problem 137
Sketch the graph of \(f\) using the following properties. (More than one correct graph is possible.) \(f\) is a piecewise function that is decreasing on \((-\infty, 2), f(2)=0, f\) is increasing on \((2, \infty),\) and the range of \(f\) is \([0, \infty)\)
3 step solution
Problem 137
During the winter, you program your home thermostat so that at midnight, the temperature is \(55^{\circ} .\) This temperature is maintained until 6 a. \(M\). Then the house begins to warm up so that by 9 A.M. the temperature is \(65^{\circ} .\) At 6 P.M. the house begins to cool. By 9 P.M., the temperature is again \(55^{\circ}\). The graph illustrates home temperature, \(f(t),\) as a function of hours after midnight, \(t\). (Graph can't copy) Using the graph at the bottom of the previous column, determine whether each statement makes sense or does not make sense, and explain your reasoning. If the statement makes sense, graph the new function on the domain \([0,24] .\) If the statement does not make sense, correct the function in the statement and graph the corrected function on the domain [0,24] I decided to keep the house \(5^{\circ}\) warmer than before, so I reprogrammed the thermostat to \(y=f(t)+5\)
4 step solution
Problem 138
Define a piecewise function on the intervals \((-\infty, 2],(2,5)\) and \([5, \infty)\) that does not "jump" at 2 or 5 such that one piece is a constant function, another piece is an increasing function, and the third piece is a decreasing function.
3 step solution
Problem 138
During the winter, you program your home thermostat so that at midnight, the temperature is \(55^{\circ} .\) This temperature is maintained until 6 a. \(M\). Then the house begins to warm up so that by 9 A.M. the temperature is \(65^{\circ} .\) At 6 P.M. the house begins to cool. By 9 P.M., the temperature is again \(55^{\circ}\). The graph illustrates home temperature, \(f(t),\) as a function of hours after midnight, \(t\). (Graph can't copy) Using the graph at the bottom of the previous column, determine whether each statement makes sense or does not make sense, and explain your reasoning. If the statement makes sense, graph the new function on the domain \([0,24] .\) If the statement does not make sense, correct the function in the statement and graph the corrected function on the domain [0,24] I decided to keep the house \(5^{\circ}\) cooler than before, so I reprogrammed the thermostat to \(y=f(t)-5\)
3 step solution
Problem 139
Suppose that \(h(x)=\frac{f(x)}{g(x)} .\) The function \(f\) can be even,odd, or neither. The same is true for the function \(g .\) a. Under what conditions is \(h\) definitely an even function? b. Under what conditions is \(h \quad\) definitely an odd function?
2 step solution
Problem 140
You invested \(\$ 80,000\) in two accounts paying \(5 \%\) and \(7 \%\) annual interest. If the total interest earned for the year was \(\$ 5200,\) how much was invested at each rate? (Section \(\mathrm{P.8}\) Example 5 )
5 step solution
Problem 141
Solve for \(A: C=A+A r\) (Section P.7, Example 5 )
3 step solution
Problem 141
Determine whether each statement is true or false. If the statement is false, make the necessary change(s) to produce a true statement. If \(f(x)=|x|\) and \(g(x)=|x+3|+3,\) then the graph of \(g\) is a translation of the graph of \(f\) three units to the right and three units upward.
3 step solution
Problem 142
Solve by the quadratic formula: \(5 x^{2}-6 x-8=0\) (Section P.7, Example 10)
4 step solution
Problem 143
Will help you prepare for the material covered in the next section. $$\text { If }\left(x_{1}, y_{1}\right)=(-3,1) \text { and }\left(x_{2}, y_{2}\right)=(-2,4), \text { find } \frac{y_{2}-y_{1}}{x_{2}-x_{1}}$$
4 step solution
Problem 144
Will help you prepare for the material covered in the next section. Find the ordered pairs \((\quad, 0)\) and \((0, \quad)\) satisfying \(4 x-3 y-6=0\).
2 step solution
Problem 144
Determine whether each statement is true or false. If the statement is false, make the necessary change(s) to produce a true statement. If \(f(x)=x^{3}\) and \(g(x)=-(x-3)^{3}-4,\) then the graph of \(g\) can be obtained from the graph of \(f\) by moving \(f\) three units to the right, reflecting about the \(x\) -axis, and then moving the resulting graph down four units.
3 step solution
Problem 145
Will help you prepare for the material covered in the next section. Solve for \(y: 3 x+2 y-4=0\)
3 step solution
Problem 150
Assume that \((a, b)\) is a point on the graph of \(f .\) What is the corresponding point on the graph of each of the following functions? $$y=2 f(x)$$
2 step solution
Problem 152
Assume that \((a, b)\) is a point on the graph of \(f .\) What is the corresponding point on the graph of each of the following functions? $$y=f(x)-3$$
3 step solution
Problem 153
The length of a rectangle exceeds the width by 13 yards. If the perimeter of the rectangle is 82 yards, what are its dimensions?
4 step solution
Problem 154
Solve: \(\sqrt{x+10}-4=x\)
6 step solution
Problem 155
If \(f(x)=x^{2}+3 x+2,\) find \(\frac{f(x+h)-f(x)}{h}, h \neq 0,\) and simplify.
3 step solution
Problem 156
Exercises \(156-158\) will help you prepare for the material covered in the next section. Perform the indicated operation or operations. $$(2 x-1)\left(x^{2}+x-2\right)$$
3 step solution
Problem 157
Exercises \(156-158\) will help you prepare for the material covered in the next section. Perform the indicated operation or operations. $$(f(x))^{2}-2 f(x)+6, \text { where } f(x)=3 x-4$$
3 step solution
Problem 158
Exercises \(156-158\) will help you prepare for the material covered in the next section. Simplify: \(\frac{2}{\frac{3}{x}-1}\)
3 step solution