Chapter 9

Introductory Algebra for College Students · 392 exercises

Problem 47

When the shot is released at an angle of \(35^{\circ},\) its height, \(y,\) in feet, can be modeled by $$y=-0.01 x^{2}+0.7 x+6.1$$ where \(x\) is the shot's horizontal distance, in feet, from its point of release. Use this model to solve parts (a) through(c) and verify your answers using the blue graph. a. What is the maximum height of the shot and how far from its point of release does this occur? b. What is the shot's maximum horizontal distance, to the nearest tenth of a foot, or the distance of the throw? c. From what height was the shot released?

3 step solution

Problem 47

Solve each equation by the method of your choice. Simplify irrational solutions, if possible $$(x+2)^{2}+x(x+1)=4$$

5 step solution

Problem 47

What is a complex number?

3 step solution

Problem 48

Your friend heard that functions are studied in intermediate and college algebra courses. He asks you what a function is. Provide him with a clear, relatively concise response.

3 step solution

Problem 48

A ball is thrown upward and outward from a height of 6 feet. The height of the ball, \(y,\) in feet, can be modeled by $$y=-0.8 x^{2}+2.4 x+6$$ where \(x\) is the ball's horizontal distance, in feet, from where it was thrown. a. What is the maximum height of the ball and how far from where it was thrown does this occur? b. How far does the ball travel horizontally before hitting the ground? Round to the nearest tenth of a foot. c. Graph the equation that models the ball's parabolic path.

3 step solution

Problem 48

Solve each equation by the method of your choice. Simplify irrational solutions, if possible $$(x-1)(3 x+2)=-7(x-1)$$

3 step solution

Problem 48

What is an imaginary number?

3 step solution

Problem 49

Does \(f(x)\) mean \(f\) times \(x\) when referring to a function \(f ?\) If not, what does \(f(x)\) mean? Provide an example with your explanation.

3 step solution

Problem 49

A ball is thrown upward and outward from a height of 6 feet. The height of the ball, \(y,\) in feet, can be modeled by $$y=-0.8 x^{2}+3.2 x+6$$ where \(x\) is the ball's horizontal distance, in feet, from where it was thrown. a. What is the maximum height of the ball and how far from where it was thrown does this occur? b. How far does the ball travel horizontally before hitting the ground? Round to the nearest tenth of a foot. c. Graph the equation that models the ball's parabolic path.

3 step solution

Problem 49

Solve each equation by the method of your choice. Simplify irrational solutions, if possible $$2 x^{2}-9 x-3=9-9 x$$

3 step solution

Problem 49

Find the distance between each pair of points. Express answers in simplified radical form and, if necessary, round to two decimal places. $$(3,5) \text { and }(4,1)$$

4 step solution

Problem 49

Why is every real number also a complex number?

3 step solution

Problem 50

Explain how the vertical line test is used to determine whether a graph is a function.

3 step solution

Problem 50

You have 120 feet of fencing to enclose a rectangular plot that borders on a river. If you do not fence the side along the river, find the length and width of the plot that will maximize the area. What is the largest area that can be enclosed?

4 step solution

Problem 50

Solve each equation by the method of your choice. Simplify irrational solutions, if possible $$3 x^{2}-6 x-3=12-6 x$$

3 step solution

Problem 50

Determine whether statement is true or false. If the statement is false, make the necessary change(s) to produce a true statement. In completing the square for \(x^{2}-7 x=5,\) we should add \(\frac{49}{4}\) to both sides.

3 step solution

Problem 50

Find the distance between each pair of points. Express answers in simplified radical form and, if necessary, round to two decimal places. $$(1,5) \text { and }(6,2)$$

4 step solution

Problem 51

For people filing a single return, federal income tax is a function of adjusted gross income. For each value of adjusted gross income, there is a specific tax to be paid. By contrast, the price of a house is not a function of the lot size on which the house sits. Houses on same-sized lots can sell for many different prices. a. Describe an everyday situation between variables that is a function. b. Describe an everyday situation between variables that is not a function.

4 step solution

Problem 51

Solve each equation by the method of your choice. Simplify irrational solutions, if possible $$\frac{1}{x}+\frac{1}{x+3}=\frac{1}{4}$$

4 step solution

Problem 51

Determine whether statement is true or false. If the statement is false, make the necessary change(s) to produce a true statement. Write a perfect square trinomial whose \(x\) -term is \(-20 x\).

4 step solution

Problem 51

Find the distance between each pair of points. Express answers in simplified radical form and, if necessary, round to two decimal places. $$(-4,2) \text { and }(4,17)$$

4 step solution

Problem 51

Determine whether each statement "makes sense" or "does not make sense" and explain your reasoning. The word imaginary in imaginary numbers tells me that These numbers are undefined.

3 step solution

Problem 52

What is a parabola? Describe its shape.

3 step solution

Problem 52

Solve each equation by the method of your choice. Simplify irrational solutions, if possible $$\frac{1}{x}+\frac{2}{x+3}=\frac{1}{4}$$

3 step solution

Problem 52

Find the distance between each pair of points. Express answers in simplified radical form and, if necessary, round to two decimal places. $$(2,-2) \text { and }(5,2)$$

4 step solution

Problem 52

Determine whether each statement "makes sense" or "does not make sense" and explain your reasoning. Writing \(i\) before any radical helps me to avoid placing \(i\) in the radicand.

3 step solution

Problem 53

Determine whether each statement "makes sense" or "does not make sense" and explain your reasoning. My height is a function of my age.

3 step solution

Problem 53

Explain how to decide whether a parabola opens upward or downward.

3 step solution

Problem 53

A football is kicked straight up from a height of 4 feet with an initial speed of 60 feet per second. The formula,$$h=-16 t^{2}+60 t+4$$ describes the ball's height above the ground, \(h\), in feet, \(t\) seconds after it is kicked. How long will it take for the football to hit the ground? Use a calculator and round to the nearest tenth of a second.

4 step solution

Problem 53

Find the distance between each pair of points. Express answers in simplified radical form and, if necessary, round to two decimal places. $$(6,-1) \text { and }(9,5)$$

5 step solution

Problem 54

If a parabola has two \(x\) -intercepts, explain how to find them.

4 step solution

Problem 54

Find the distance between each pair of points. Express answers in simplified radical form and, if necessary, round to two decimal places. $$(-4,-1) \text { and }(2,-3)$$

5 step solution

Problem 54

Determine whether each statement "makes sense" or "does not make sense" and explain your reasoning. When I use the quadratic formula to solve a quadratic equation and \(b^{2}-4 a c\) is negative, I can be certain that the equation has two imaginary solutions.

3 step solution

Problem 55

Explain how to find a parabola's \(y\) -intercept.

4 step solution

Problem 55

Perform the indicated operations. If possible, simplify the answer. \(\frac{2 x+3}{x^{2}-7 x+12}-\frac{2}{x-3}(\) Section 7.4 , Example 7 )

4 step solution

Problem 55

Find the distance between each pair of points. Express answers in simplified radical form and, if necessary, round to two decimal places. $$(-7,-5) \text { and }(-2,-1)$$

3 step solution

Problem 56

Describe how to find a parabola's vertex.

3 step solution

Problem 56

Perform the indicated operations. If possible, simplify the answer. \(\frac{x-\frac{1}{3}}{3-\frac{1}{x}}\) (Section 7.5, Example 2 or Example 5)

4 step solution

Problem 56

Find the distance between each pair of points. Express answers in simplified radical form and, if necessary, round to two decimal places. $$(-8,-4) \text { and }(-3,-8)$$

3 step solution

Problem 56

Determine whether each statement is true or false. If the statement is false, make the necessary change(s) to produce a true statement. The complex number \(a+0 i\) is the real number \(a\).

3 step solution

Problem 57

Solve: \(\sqrt{2 x+3}=2 x-3 .\) (Section 8.5, Example 4)

5 step solution

Problem 57

Find the distance between each pair of points. Express answers in simplified radical form and, if necessary, round to two decimal places. $$(-2 \sqrt{7}, 10) \text { and }(4 \sqrt{7}, 8)$$

4 step solution

Problem 57

Determine whether each statement is true or false. If the statement is false, make the necessary change(s) to produce a true statement. $$2+\sqrt{-4}=2-2 i$$

4 step solution

Problem 58

Determine whether each statement is true or false. If the statement is false, make the necessary change(s) to produce a true statement. $$\frac{2 \pm 4 i}{2}=1 \pm 4 i$$

4 step solution

Problem 58

Determine whether each statement "makes sense" or "does not make sense" and explain your reasoning. I must have made an error when graphing this parabola because it is symmetric with respect to the \(y\) -axis

3 step solution

Problem 58

Will help you prepare for the material covered in the next section. In each exercise, evaluate $$\frac{-b \pm \sqrt{b^{2}-4 a c}}{2 a}$$ for the given values of \(a, b,\) and \(c .\) Where necessary, express answers in simplified radical form. \(a=2, b=9, c=-5\)

4 step solution

Problem 58

Find the distance between each pair of points. Express answers in simplified radical form and, if necessary, round to two decimal places. $$(-\sqrt{3}, 4 \sqrt{6}) \text { and }(2 \sqrt{3}, \sqrt{6})$$

3 step solution

Problem 59

Determine whether each statement is true or false. If the statement is false, make the necessary change(s) to produce a true statement. A horizontal line can intersect the graph of a function at more than one point.

3 step solution

Problem 59

The length of a rectangle is 3 meters longer than the width. If the area is 36 square meters, find the rectangle's dimensions. Round to the nearest tenth of a meter.

4 step solution

Problem 59

Will help you prepare for the material covered in the next section. In each exercise, evaluate $$\frac{-b \pm \sqrt{b^{2}-4 a c}}{2 a}$$ for the given values of \(a, b,\) and \(c .\) Where necessary, express answers in simplified radical form. \(a=9, b=-12, c=4\)

3 step solution

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