Chapter 5

A Graphical Approach to Precalculus with Limits · 378 exercises

Problem 40

Use a calculator to find each root or power. Give as many digits as your display shows. $$15^{-1 / 6}$$

4 step solution

Problem 41

Sketch a graph of rational function. Your graph should include all asymptotes. Do not use a calculator. $$f(x)=\frac{x+2}{x-3}$$

5 step solution

Problem 41

Use an analytic method to solve each equation in part (a). Support the solution with a graph. Then use the graph to solve the inequalities in parts (b) and (c). (a) \(\sqrt[3]{x^{2}-2 x}=\sqrt[3]{x}\) (b) \(\sqrt[3]{x^{2}-2 x}>\sqrt[3]{x}\) (c) \(\sqrt[3]{x^{2}-2 x}<\sqrt[3]{x}\)

7 step solution

Problem 41

Use a calculator to find each root or power. Give as many digits as your display shows. $$32^{0.2}$$

4 step solution

Problem 42

Sketch a graph of rational function. Your graph should include all asymptotes. Do not use a calculator. $$f(x)=\frac{x-3}{x+4}$$

5 step solution

Problem 42

Use an analytic method to solve each equation in part (a). Support the solution with a graph. Then use the graph to solve the inequalities in parts (b) and (c). (a) \(\sqrt[3]{4 x^{2}-4 x+1}=\sqrt[3]{x}\) (b) \(\sqrt[3]{4 x^{2}-4 x+1}>\sqrt[3]{x}\) (c) \(\sqrt[3]{4 x^{2}-4 x+1}<\sqrt[3]{x}\)

6 step solution

Problem 42

Use a calculator to find each root or power. Give as many digits as your display shows. $$81^{0.25}$$

6 step solution

Problem 43

Solve each equation and inequality. (These types of equations and inequalities occur in calculus.) (a) \(\frac{(x-2)(2)-(2 x+1)(1)}{(x-2)^{2}}=0\) (b) \(\frac{(x-2)(2)-(2 x+1)(1)}{(x-2)^{2}}<0\)

5 step solution

Problem 43

Sketch a graph of rational function. Your graph should include all asymptotes. Do not use a calculator. $$f(x)=\frac{4-2 x}{8-x}$$

5 step solution

Problem 43

Use an analytic method to solve each equation in part (a). Support the solution with a graph. Then use the graph to solve the inequalities in parts (b) and (c). (a) \(\sqrt[4]{3 x+1}=1\) (b) \(\sqrt[4]{3 x+1}>1\) (c) \(\sqrt[4]{3 x+1}<1\)

4 step solution

Problem 43

Use a calculator to find each root or power. Give as many digits as your display shows. $$\left(\frac{5}{6}\right)^{-1.3}$$

5 step solution

Problem 44

Solve each equation and inequality. (These types of equations and inequalities occur in calculus.) (a) \(\frac{\left(x^{2}-1\right)(1)-(x+1)(2 x)}{\left(x^{2}-1\right)^{2}}=0\) (b) \(\frac{\left(x^{2}-1\right)(1)-(x+1)(2 x)}{\left(x^{2}-1\right)^{2}}>0\)

4 step solution

Problem 44

Sketch a graph of rational function. Your graph should include all asymptotes. Do not use a calculator. $$f(x)=\frac{6-3 x}{4-x}$$

5 step solution

Problem 44

Use an analytic method to solve each equation in part (a). Support the solution with a graph. Then use the graph to solve the inequalities in parts (b) and (c). (a) \(\sqrt[4]{x-15}=2\) (b) \(\sqrt[4]{x-15}>2\) (c) \(\sqrt[4]{x-15}<2\)

6 step solution

Problem 44

Use a calculator to find each root or power. Give as many digits as your display shows. $$\left(\frac{4}{7}\right)^{-0,6}$$

3 step solution

Problem 45

Solve each equation and inequality. (These types of equations and inequalities occur in calculus.) (a) \(\frac{\left(x^{2}+1\right)(2 x)-\left(x^{2}-1\right)(2 x)}{\left(x^{2}+1\right)^{2}}=0\) (b) \(\frac{\left(x^{2}+1\right)(2 x)-\left(x^{2}-1\right)(2 x)}{\left(x^{2}+1\right)^{2}} \geq 0\)

5 step solution

Problem 45

Sketch a graph of rational function. Your graph should include all asymptotes. Do not use a calculator. $$f(x)=\frac{3 x}{(x+1)(x-2)}$$

6 step solution

Problem 45

Use an analytic method to solve each equation in part (a). Support the solution with a graph. Then use the graph to solve the inequalities in parts (b) and (c). (a) \((2 x-5)^{1 / 2}-2=(x-2)^{1 / 2}\) (b) \((2 x-5)^{1 / 2}-2 \geq(x-2)^{1 / 2}\) (c) \((2 x-5)^{1 / 2}-2 \leq(x-2)^{1 / 2}\)

9 step solution

Problem 45

Use a calculator to find each root or power. Give as many digits as your display shows. $$\pi^{-3}$$

4 step solution

Problem 46

Solve each equation and inequality. (These types of equations and inequalities occur in calculus.) (a) \(\frac{\left(x^{2}-1\right)(3)-(3 x-1)(2 x)}{\left(x^{2}-1\right)^{2}}=0\) (b) \(\frac{\left(x^{2}-1\right)(3)-(3 x-1)(2 x)}{\left(x^{2}-1\right)^{2}} \leq 0\)

2 step solution

Problem 46

Sketch a graph of rational function. Your graph should include all asymptotes. Do not use a calculator. $$f(x)=\frac{2 x+1}{(x+2)(x+4)}$$

6 step solution

Problem 46

Use an analytic method to solve each equation in part (a). Support the solution with a graph. Then use the graph to solve the inequalities in parts (b) and (c). (a) \((x+5)^{1 / 2}-2=(x-1)^{1 / 2}\) (b) \((x+5)^{1 / 2}-2 \geq(x-1)^{1 / 2}\) (c) \((x+5)^{1 / 2}-2 \leq(x-1)^{1 / 2}\)

7 step solution

Problem 46

Use a calculator to find each root or power. Give as many digits as your display shows. $$(2 \pi)^{43}$$

3 step solution

Problem 47

Solve each equation and inequality. (These types of equations and inequalities occur in calculus.) (a) \(\frac{(2 x+1)(2 x)-\left(x^{2}+1\right)(2)}{(2 x+1)^{2}}=0\) (b) \(\frac{(2 x+1)(2 x)-\left(x^{2}+1\right)(2)}{(2 x+1)^{2}}<0\)

10 step solution

Problem 47

Sketch a graph of rational function. Your graph should include all asymptotes. Do not use a calculator. $$f(x)=\frac{x^{2}}{x^{2}-4}$$

7 step solution

Problem 47

Use an analytic method to solve each equation in part (a). Support the solution with a graph. Then use the graph to solve the inequalities in parts (b) and (c). (a) \(\left(x^{2}+6 x\right)^{1 / 4}=2\) (b) \(\left(x^{2}+6 x\right)^{1 / 4}>2\) (c) \(\left(x^{2}+6 x\right)^{1 / 4}<2\)

7 step solution

Problem 47

Evaluate \(f(x)\) at the given \(x\). Approximate each result to the nearest hundredth. $$f(x)=x^{1.62}, \quad x=1.2$$

3 step solution

Problem 48

Solve each equation and inequality. (These types of equations and inequalities occur in calculus.) (a) \(\frac{(x-1)(2 x)-\left(x^{2}\right)(1)}{(x-1)^{2}}=0\) (b) \(\frac{(x-1)(2 x)-\left(x^{2}\right)(1)}{(x-1)^{2}}>0\)

8 step solution

Problem 48

Sketch a graph of rational function. Your graph should include all asymptotes. Do not use a calculator. $$f(x)=\frac{x^{2}-4}{2 x^{2}-2}$$

5 step solution

Problem 48

Use an analytic method to solve each equation in part (a). Support the solution with a graph. Then use the graph to solve the inequalities in parts (b) and (c). (a) \(\left(x^{2}+2 x\right)^{1 / 4}=3^{1 / 4}\) (b) \(\left(x^{2}+2 x\right)^{1 / 4}>3^{1 / 4}\) (c) \(\left(x^{2}+2 x\right)^{1 / 4}<3^{1 / 4}\)

5 step solution

Problem 48

Evaluate \(f(x)\) at the given \(x\). Approximate each result to the nearest hundredth. $$f(x)=x^{-0.71}, \quad x=3.8$$

5 step solution

Problem 49

CONCEPT CHECK In some cases, it is possible to solve a rational inequality simply by deciding what sign the numerator and the denominator must have and then using the rules for quotients of positive and negative numbers to determine the solution set. For example, consider the rational inequality $$ \frac{1}{x^{2}+1}>0 $$ The numerator of the rational expression, 1, is positive, and the denominator, \(x^{2}+1,\) must always be positive because it is the sum of a nonnegative number, \(x^{2},\) and a positive number, 1. Therefore, the rational expression is the quotient of two positive numbers, which is positive. Because the inequality requires that the rational expression be greater than \(0,\) and this will always be true, the solution set is \((-\infty, \infty)\) Use similar reasoning to solve each inequality. $$\frac{-1}{x^{2}+2}<0$$

6 step solution

Problem 49

Sketch a graph of rational function. Your graph should include all asymptotes. Do not use a calculator. $$f(x)=\frac{x^{2}}{1-x^{2}}$$

5 step solution

Problem 49

Evaluate \(f(x)\) at the given \(x\). Approximate each result to the nearest hundredth. $$f(x)=x^{3 / 2}-x^{1 / 2}, \quad x=50$$

6 step solution

Problem 50

CONCEPT CHECK In some cases, it is possible to solve a rational inequality simply by deciding what sign the numerator and the denominator must have and then using the rules for quotients of positive and negative numbers to determine the solution set. For example, consider the rational inequality $$ \frac{1}{x^{2}+1}>0 $$ The numerator of the rational expression, 1, is positive, and the denominator, \(x^{2}+1,\) must always be positive because it is the sum of a nonnegative number, \(x^{2},\) and a positive number, 1. Therefore, the rational expression is the quotient of two positive numbers, which is positive. Because the inequality requires that the rational expression be greater than \(0,\) and this will always be true, the solution set is \((-\infty, \infty)\) Use similar reasoning to solve each inequality. $$\frac{5}{x^{2}+2}<0$$

4 step solution

Problem 50

Sketch a graph of rational function. Your graph should include all asymptotes. Do not use a calculator. $$f(x)=\frac{1-x^{2}}{2 x^{2}}$$

6 step solution

Problem 50

Use an analytic method to solve each equation in part (a). Support the solution with a graph. Then use the graph to solve the inequalities in parts (b) and (c). (a) \((x-3)^{2 / 5}=(4 x)^{1 / 5}\) (b) \((x-3)^{2 / 5}>(4 x)^{1 / 5}\) (c) \((x-3)^{2 / 5}<(4 x)^{1 / 5}\)

7 step solution

Problem 50

Evaluate \(f(x)\) at the given \(x\). Approximate each result to the nearest hundredth. $$f(x)=x^{5 / 4}-x^{-3 / 4}, \quad x=7$$

5 step solution

Problem 51

CONCEPT CHECK In some cases, it is possible to solve a rational inequality simply by deciding what sign the numerator and the denominator must have and then using the rules for quotients of positive and negative numbers to determine the solution set. For example, consider the rational inequality $$ \frac{1}{x^{2}+1}>0 $$ The numerator of the rational expression, 1, is positive, and the denominator, \(x^{2}+1,\) must always be positive because it is the sum of a nonnegative number, \(x^{2},\) and a positive number, 1. Therefore, the rational expression is the quotient of two positive numbers, which is positive. Because the inequality requires that the rational expression be greater than \(0,\) and this will always be true, the solution set is \((-\infty, \infty)\) Use similar reasoning to solve each inequality. $$\frac{-5}{x^{2}+2}>0$$

4 step solution

Problem 51

Sketch a graph of rational function. Your graph should include all asymptotes. Do not use a calculator. $$f(x)=\frac{5 x}{x^{2}-1}$$

5 step solution

Problem 51

Use analytic or graphical methods to solve the inequality. $$\sqrt{2 x+3}>3$$

4 step solution

Problem 52

CONCEPT CHECK In some cases, it is possible to solve a rational inequality simply by deciding what sign the numerator and the denominator must have and then using the rules for quotients of positive and negative numbers to determine the solution set. For example, consider the rational inequality $$ \frac{1}{x^{2}+1}>0 $$ The numerator of the rational expression, 1, is positive, and the denominator, \(x^{2}+1,\) must always be positive because it is the sum of a nonnegative number, \(x^{2},\) and a positive number, 1. Therefore, the rational expression is the quotient of two positive numbers, which is positive. Because the inequality requires that the rational expression be greater than \(0,\) and this will always be true, the solution set is \((-\infty, \infty)\) Use similar reasoning to solve each inequality. $$\frac{x^{4}+2}{-6} \leq 0$$

6 step solution

Problem 52

Sketch a graph of rational function. Your graph should include all asymptotes. Do not use a calculator. $$f(x)=\frac{x}{4-x^{2}}$$

4 step solution

Problem 52

Use analytic or graphical methods to solve the inequality. $$\sqrt{3 x-5} \leq 4$$

6 step solution

Problem 53

CONCEPT CHECK In some cases, it is possible to solve a rational inequality simply by deciding what sign the numerator and the denominator must have and then using the rules for quotients of positive and negative numbers to determine the solution set. For example, consider the rational inequality $$ \frac{1}{x^{2}+1}>0 $$ The numerator of the rational expression, 1, is positive, and the denominator, \(x^{2}+1,\) must always be positive because it is the sum of a nonnegative number, \(x^{2},\) and a positive number, 1. Therefore, the rational expression is the quotient of two positive numbers, which is positive. Because the inequality requires that the rational expression be greater than \(0,\) and this will always be true, the solution set is \((-\infty, \infty)\) Use similar reasoning to solve each inequality. $$\frac{x^{4}+2}{-6} \geq 0$$

5 step solution

Problem 53

Sketch a graph of rational function. Your graph should include all asymptotes. Do not use a calculator. $$f(x)=\frac{(x+6)(x-2)}{(x+3)(x-4)}$$

6 step solution

Problem 53

Use analytic or graphical methods to solve the inequality. $$\sqrt{2 x-2}-1<\sqrt{x}$$

8 step solution

Problem 54

CONCEPT CHECK In some cases, it is possible to solve a rational inequality simply by deciding what sign the numerator and the denominator must have and then using the rules for quotients of positive and negative numbers to determine the solution set. For example, consider the rational inequality $$ \frac{1}{x^{2}+1}>0 $$ The numerator of the rational expression, 1, is positive, and the denominator, \(x^{2}+1,\) must always be positive because it is the sum of a nonnegative number, \(x^{2},\) and a positive number, 1. Therefore, the rational expression is the quotient of two positive numbers, which is positive. Because the inequality requires that the rational expression be greater than \(0,\) and this will always be true, the solution set is \((-\infty, \infty)\) Use similar reasoning to solve each inequality. $$\frac{x^{4}+x^{2}+3}{x^{2}+2}<0$$

5 step solution

Problem 54

Sketch a graph of rational function. Your graph should include all asymptotes. Do not use a calculator. $$f(x)=\frac{(x+3)(x-5)}{(x+1)(x-4)}$$

5 step solution

Problem 54

Use analytic or graphical methods to solve the inequality. $$\sqrt{4 x}-1 \geq \sqrt{2 x+1}$$

9 step solution

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