Chapter 2

College Algebra · 450 exercises

Problem 44

What is the total distance that two people travel in 3 \(\mathrm{h}\) if one of them is riding a bike at 15 \(\mathrm{mi} / \mathrm{h}\) and the other is walking at 3 \(\mathrm{mi} / \mathrm{h}\) ?

3 step solution

Problem 44

For the following exercises, use a calculator to help answer the questions. Evaluate \((l+i)^{k}-(l-i)^{k}\) for \(k=4,8\), and 12 . Predict the value for \(k=16\).

4 step solution

Problem 44

enter the expressions into your graphing utility and find the zeroes to the equation (the x-intercepts) by using \(2^{\text { nd }}\) CALC \(2 :\) zero. Recall finding zeroes will ask left bound (move your cursor to the left of the zero, enter), then right bound (move your cursor to the right of the zero, enter), then guess (move your cursor between the bounds near the zero, enter). Round your answers to the nearest thousandth. $$\mathrm{Y}_{1}=4 x^{2}+3 x-2$$

7 step solution

Problem 45

For the following exercises, write the set in interval notation. $$ \\{x | x < 4\\} $$

3 step solution

Problem 45

For the following exercises, solve for the unknown variable. $$ \left|x^{2}+2 x-36\right|=12 $$

4 step solution

Problem 45

Write the set in interval notation. $$ \\{x \mid x<4\\} $$

4 step solution

Problem 45

For the following exercises, find the slope of the lines that pass through each pair of points and determine whether the lines are parallel or perpendicular. \((-1,3)\) and \((5,1)\) \((-2,3)\) and \((0,9)\)

4 step solution

Problem 45

If the area model for a triangle is \(A=\frac{1}{2} b h,\) find the area of a triangle with a height of 16 in. and a base of 11 in.

5 step solution

Problem 45

Enter the expressions into your graphing utility and find the zeroes to the equation (the \(x\) -intercepts) by using \(2^{\text {nd }}\) CALC 2 :zero. Recall finding zeroes will ask left bound (move your cursor to the left of the zero, enter), then right bound (move your cursor to the right of the zero, enter), then guess (move your cursor between the bounds near the zero, enter). Round your answers to the nearest thousandth. $$ \mathrm{Y}_{1}=-3 x^{2}+8 x-1 $$

6 step solution

Problem 45

For each of the following exercises, use the graph in the figure below. Find the distance that \((-3,4)\) is from the origin.

6 step solution

Problem 46

For the following exercises, write the set in interval notation. $$ \\{x | x \text { is all real numbers }\\} $$

3 step solution

Problem 46

For the following exercises, use the model for the period of a pendulum, \(T\), such that \(T=2 \pi \sqrt{\frac{L}{g}}\), where the length of the pendulum is \(L\) and the acceleration due to gravity is \(g\). If the acceleration due to gravity is \(9.8 \mathrm{~m} / \mathrm{s}^{2}\) and the period equals \(1 \mathrm{~s}, \mathrm{fi}\) d the length to the nearest \(\mathrm{cm}\) \((100 \mathrm{~cm}=1 \mathrm{~m})\)

6 step solution

Problem 46

Write the set in interval notation. $$ \\{x \mid x \text { is all real numbers }\\} $$

3 step solution

Problem 46

For the following exercises, find the slope of the lines that pass through each pair of points and determine whether the lines are parallel or perpendicular. \((2,5)\) and \((5,9)\) \((-1,-1)\) and \((2,3)\)

3 step solution

Problem 46

For the following exercises, use a calculator to help answer the questions. Show that a solution of \(x^{8}-1=0\) is \(\frac{\sqrt{2}}{2}+\frac{\sqrt{2}}{2} i\).

3 step solution

Problem 46

Enter the expressions into your graphing utility and find the zeroes to the equation (the \(x\) -intercepts) by using \(2^{\text {nd }}\) CALC 2 :zero. Recall finding zeroes will ask left bound (move your cursor to the left of the zero, enter), then right bound (move your cursor to the right of the zero, enter), then guess (move your cursor between the bounds near the zero, enter). Round your answers to the nearest thousandth. $$ \mathrm{Y}_{1}=0.5 x^{2}+x-7 $$

7 step solution

Problem 46

For each of the following exercises, use the graph in the figure below. Find the distance that \((5,2)\) is from the origin. Round to three decimal places.

6 step solution

Problem 46

Solve for \(h: A=\frac{1}{2} b h\)

3 step solution

Problem 47

For the following exercises, write the interval in set-builder notation. $$ (-\infty, 6) $$

3 step solution

Problem 47

For the following exercises, use the model for the period of a pendulum, \(T\), such that \(T=2 \pi \sqrt{\frac{L}{g}}\), where the length of the pendulum is \(L\) and the acceleration due to gravity is \(g\). If the gravity is \(32 \mathrm{ft} /{ }^{2}\) and the period equals \(1 \mathrm{~s}\), fi d the length to the nearest in. (12 in. = \(1 \mathrm{ft}\) ). Round your answer to the nearest in.

6 step solution

Problem 47

Write the interval in set-builder notation. $$ (-\infty, 6) $$

3 step solution

Problem 47

For the following exercises, express the equations in slope intercept form (rounding each number to the thousandths place). Enter this into a graphing calculator as Y1, then adjust the ymin and ymax values for your window to include where the y-intercept occurs. State your ymin and ymax values. \(0.537 x-2.19 y=100\)

5 step solution

Problem 47

For the following exercises, evaluate the expressions, writing the result as a simplified complex number. $$ \frac{1}{i}+\frac{4}{i^{3}} $$

5 step solution

Problem 47

To solve the quadratic equation \(x^{2}+5 x-7=4,\) we can graph these two equations \(\mathrm{Y}_{1}=x^{2}+5 x-7 \qquad \mathrm{Y}_{2}=4\) and find the points of intersection. Recall \(2^{\text { nd }} \mathrm{CALC} \) 5 intersection. Do this and find the solutions to the nearest tenth.

5 step solution

Problem 48

For the following exercises, write the interval in set-builder notation. $$ (4, \infty) $$

2 step solution

Problem 48

Write the interval in set-builder notation. $$ (4, \infty) $$

4 step solution

Problem 48

For the following exercises, express the equations in slope intercept form (rounding each number to the thousandths place). Enter this into a graphing calculator as Y1, then adjust the ymin and ymax values for your window to include where the y-intercept occurs. State your ymin and ymax values. \(4,500 x-200 y=9,528\)

4 step solution

Problem 48

For the following exercises, use a model for body surface area, BSA, such that \(B S A=\sqrt{\frac{w h}{3600}},\) where \(w=\) weight in \(\mathrm{kg}\) and \(h=\) height in \(\mathrm{cm} .\) Find the height of a 72 -kg female to the nearest cm whose \(B S A=1.8 .\)

6 step solution

Problem 48

The volume formula for a cylinder is \(V=\pi r^{2} h\) Using the symbol \(\pi\) in your answer, find the volume of a cylinder with a radius, \(r,\) of 4 \(\mathrm{cm}\) and a height of 14 \(\mathrm{cm} .\)

6 step solution

Problem 48

For the following exercises, evaluate the expressions, writing the result as a simplified complex number. $$ \frac{1}{i^{11}}-\frac{1}{i^{21}} $$

5 step solution

Problem 48

To solve the quadratic equation \(0.3 x^{2}+2 x-4=2\) , we can graph these two equations \(\mathrm{Y}_{1}=0.3 x^{2}+2 x-4 \qquad \mathrm{Y}_{2}=2\) and find the points of intersewction. Recall \(2^{\text { nd }} \mathrm{CALC}\) 5 intersection. Do this and find the solutions to the nearest tenth.

4 step solution

Problem 48

After graphing it, use the \(2^{\text {nd }}\) CALC button and 1:value button, hit ENTER. At the lower part of the screen you will see " \(\mathbf{x}=\) " and a blinking cursor. You may enter any number for \(x\) and it will display the \(y\) value for any \(x\) value you input. Use this and plug in \(x=0\), thus finding the \(y\) -intercept, for each of the following graphs. $$ Y_{1}=-2 x+5 $$

5 step solution

Problem 49

For the following exercises, write the interval in set-builder notation. $$ [-3,5) $$

2 step solution

Problem 49

Write the interval in set-builder notation. $$ [-3,5) $$

3 step solution

Problem 49

For the following exercises, express the equations in slope intercept form (rounding each number to the thousandths place). Enter this into a graphing calculator as Y1, then adjust the ymin and ymax values for your window to include where the y-intercept occurs. State your ymin and ymax values. \(\frac{200-30 y}{x}=70\)

6 step solution

Problem 49

For the following exercises, use a model for body surface area, BSA, such that \(B S A=\sqrt{\frac{w h}{3600}},\) where \(w=\) weight in \(\mathrm{kg}\) and \(h=\) height in \(\mathrm{cm} .\) Find the weight of a 177 -cm male to the nearest kg whose \(B S A=2.1 .\)

7 step solution

Problem 49

For the following exercises, evaluate the expressions, writing the result as a simplified complex number. $$ i^{7}\left(1+i^{2}\right) $$

4 step solution

Problem 49

Solve for \(h : V=\pi r^{2} h\)

3 step solution

Problem 49

Beginning with the general form of a quadratic equation, \(a x^{2}+b x+c=0,\) solve for \(x\) by using the completing the square method, thus deriving the quadratic formula.

8 step solution

Problem 49

After graphing it, use the \(2^{\text {nd }}\) CALC button and 1:value button, hit ENTER. At the lower part of the screen you will see " \(\mathbf{x}=\) " and a blinking cursor. You may enter any number for \(x\) and it will display the \(y\) value for any \(x\) value you input. Use this and plug in \(x=0\), thus finding the \(y\) -intercept, for each of the following graphs. $$ \mathrm{Y}_{1}=\frac{3 x-8}{4} $$

3 step solution

Problem 50

For the following exercises, write the interval in set-builder notation. $$ [-4,1] \cup[9, \infty) $$

4 step solution

Problem 50

Write the interval in set-builder notation. $$ [-4,1] \cup[9, \infty) $$

3 step solution

Problem 50

Starting with the point-slope formula \(y-y_{1}=m\left(x-x_{1}\right),\) solve this expression for \(x\) in terms of \(x_{1}, y, y_{1},\) and \(m .\)

4 step solution

Problem 50

For the following exercises, evaluate the expressions, writing the result as a simplified complex number. $$ i^{-3}+5 i^{7} $$

4 step solution

Problem 50

Show that the sum of the two solutions to the quadratic equation is \(-\frac{b}{a}\) .

6 step solution

Problem 50

After graphing it, use the \(2^{\text {nd }}\) CALC button and 1:value button, hit ENTER. At the lower part of the screen you will see " \(\mathbf{x}=\) " and a blinking cursor. You may enter any number for \(x\) and it will display the \(y\) value for any \(x\) value you input. Use this and plug in \(x=0\), thus finding the \(y\) -intercept, for each of the following graphs. $$ \mathrm{Y}_{1}=\frac{x+5}{2} $$

5 step solution

Problem 51

Starting with the standard form of an equation \(A x+B y=C,\) solve this expression for \(y\) in terms of \(A, B, C,\) and \(x .\) Then put the expression in slope-intercept form.

4 step solution

Problem 51

Solve for \(r : V=\pi r^{2} h\)

4 step solution

Problem 51

For the following exercises, evaluate the expressions, writing the result as a simplified complex number. $$ \frac{(2+i)(4-2 i)}{(1+i)} $$

4 step solution

Problem 51

A person has a garden that has a length 10 feet longer than the width. Set up a quadratic equation to find the dimensions of the garden if its area is 119 \(\mathrm{ft}^{2}\) . Solve the quadratic equation to find the length and width.

7 step solution

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