Chapter 1

Algebra and Trigonometry · 541 exercises

Problem 61

Use the discriminant to determine the number of real solutions of the equation. Do not solve the equation. \(x^{2}-6 x+1=0\)

4 step solution

Problem 61

\(47-70\) The given equation involves a power of the variable. Find all real solutions of the equation. $$ x^{4}+64=0 $$

7 step solution

Problem 62

\(33-66\) . Solve the nonlinear inequality. Express the solution using interval notation and graph the solution set. $$ \frac{x}{2} \geq \frac{5}{x+1}+4 $$

6 step solution

Problem 62

Find all solutions of the equation and express them in the form \(a+b i .\) $$ z+4+\frac{12}{z}=0 $$

7 step solution

Problem 62

55–64 ? Find all solutions, real and complex, of the equation. $$ x^{6}+9 x^{4}-4 x^{2}-36=0 $$

5 step solution

Problem 62

Use the discriminant to determine the number of real solutions of the equation. Do not solve the equation. \(x^{2}=6 x-9\)

4 step solution

Problem 62

\(47-70\) The given equation involves a power of the variable. Find all real solutions of the equation. $$ (x-1)^{3}+8=0 $$

4 step solution

Problem 63

\(33-66\) . Solve the nonlinear inequality. Express the solution using interval notation and graph the solution set. $$ \frac{x+2}{x+3}<\frac{x-1}{x-2} $$

7 step solution

Problem 63

Find all solutions of the equation and express them in the form \(a+b i .\) $$ 6 x^{2}+12 x+7=0 $$

6 step solution

Problem 63

55–64 ? Find all solutions, real and complex, of the equation. $$ \sqrt{x^{2}+1}+\frac{8}{\sqrt{x^{2}+1}}=\sqrt{x^{2}+9} $$

7 step solution

Problem 63

Use the discriminant to determine the number of real solutions of the equation. Do not solve the equation. \(x^{2}+2.20 x+1.21=0\)

3 step solution

Problem 63

\(47-70\) The given equation involves a power of the variable. Find all real solutions of the equation. $$ (x+2)^{4}-81=0 $$

5 step solution

Problem 64

\(33-66\) . Solve the nonlinear inequality. Express the solution using interval notation and graph the solution set. $$ \frac{1}{x+1}+\frac{1}{x+2} \leq 0 $$

7 step solution

Problem 64

Find all solutions of the equation and express them in the form \(a+b i .\) $$ 4 x^{2}-16 x+19=0 $$

6 step solution

Problem 64

55–64 ? Find all solutions, real and complex, of the equation. $$ 1-\sqrt{x^{2}+7}=6-x^{2} $$

8 step solution

Problem 64

Use the discriminant to determine the number of real solutions of the equation. Do not solve the equation. \(x^{2}+2.21 x+1.21=0\)

5 step solution

Problem 64

\(47-70\) The given equation involves a power of the variable. Find all real solutions of the equation. $$ (x+1)^{4}+16=0 $$

4 step solution

Problem 65

\(33-66\) . Solve the nonlinear inequality. Express the solution using interval notation and graph the solution set. $$ x^{4}>x^{2} $$

7 step solution

Problem 65

Find all solutions of the equation and express them in the form \(a+b i .\) $$ \frac{1}{2} x^{2}-x+5=0 $$

5 step solution

Problem 65

65–68 ? Solve the equation for the variable x. The constants a and b represent positive real numbers. $$ x^{4}+5 a x^{2}+4 a^{2}=0 $$

6 step solution

Problem 65

Use the discriminant to determine the number of real solutions of the equation. Do not solve the equation. \(4 x^{2}+5 x+\frac{13}{8}=0\)

5 step solution

Problem 65

\(47-70\) The given equation involves a power of the variable. Find all real solutions of the equation. $$ 3(x-3)^{3}=375 $$

4 step solution

Problem 66

\(33-66\) . Solve the nonlinear inequality. Express the solution using interval notation and graph the solution set. $$ x^{5}>x^{2} $$

9 step solution

Problem 66

Find all solutions of the equation and express them in the form \(a+b i .\) $$ x^{2}+\frac{1}{2} x+1=0 $$

6 step solution

Problem 66

65–68 ? Solve the equation for the variable x. The constants a and b represent positive real numbers. $$ a^{3} x^{3}+b^{3}=0 $$

5 step solution

Problem 66

Use the discriminant to determine the number of real solutions of the equation. Do not solve the equation. \(9 x^{2}-4 x+\frac{4}{9}=0\)

4 step solution

Problem 66

\(47-70\) The given equation involves a power of the variable. Find all real solutions of the equation. $$ 4(x+2)^{5}=1 $$

4 step solution

Problem 67

\(67-70=\) Determine the values of the variable for which the expression is defined as a real number. $$ \sqrt{16-9 x^{2}} $$

5 step solution

Problem 67

Recall that the symbol \(\overline{z}\) represents the complex con- jugate of \(z .\) If \(z=a+b i\) and \(w=c+d i,\) prove each statement. $$ \overline{z}+\overline{w}=\overline{z+w} $$

5 step solution

Problem 67

65–68 ? Solve the equation for the variable x. The constants a and b represent positive real numbers. $$ \sqrt{x+a}+\sqrt{x-a}=\sqrt{2} \sqrt{x+6} $$

7 step solution

Problem 67

Use the discriminant to determine the number of real solutions of the equation. Do not solve the equation. \(x^{2}+r x-s=0 \quad(s>0)\)

5 step solution

Problem 67

\(47-70\) The given equation involves a power of the variable. Find all real solutions of the equation. $$ \sqrt[3]{x}=5 $$

3 step solution

Problem 68

\(67-70=\) Determine the values of the variable for which the expression is defined as a real number. $$ \sqrt{3 x^{2}-5 x+2} $$

7 step solution

Problem 68

Recall that the symbol \(\overline{z}\) represents the complex con- jugate of \(z .\) If \(z=a+b i\) and \(w=c+d i,\) prove each statement. $$ \overline{z w}=\overline{z} \cdot \overline{w} $$

4 step solution

Problem 68

65–68 ? Solve the equation for the variable x. The constants a and b represent positive real numbers. $$ \sqrt{x}+a \sqrt[3]{x}+b \sqrt[6]{x}+a b=0 $$

6 step solution

Problem 68

Use the discriminant to determine the number of real solutions of the equation. Do not solve the equation. \(x^{2}-r x+s=0 \quad(s>0, r>2 \sqrt{s})\)

5 step solution

Problem 68

\(47-70\) The given equation involves a power of the variable. Find all real solutions of the equation. $$ x^{4 / 3}-16=0 $$

5 step solution

Problem 69

\(67-70=\) Determine the values of the variable for which the expression is defined as a real number. $$ \left(\frac{1}{x^{2}-5 x-14}\right)^{1 / 2} $$

7 step solution

Problem 69

Recall that the symbol \(\overline{z}\) represents the complex con- jugate of \(z .\) If \(z=a+b i\) and \(w=c+d i,\) prove each statement. $$ (\overline{z})^{2}=\overline{z^{2}} $$

5 step solution

Problem 69

Chartering a Bus A social club charters a bus at a cost of \(\$ 900\) to take a group of members on an excursion to Atlantic City. At the last minute, five people in the group decide not to go. This raises the transportation cost per person by \(\$ 2 .\) How many people originally intended to take the trip?

9 step solution

Problem 69

Solve the equation for \(x\). \(a^{2} x^{2}+2 a x+1=0 \quad(a \neq 0)\)

4 step solution

Problem 69

\(47-70\) The given equation involves a power of the variable. Find all real solutions of the equation. $$ 2 x^{5 / 3}+64=0 $$

4 step solution

Problem 70

\(67-70=\) Determine the values of the variable for which the expression is defined as a real number. $$ \sqrt[4]{\frac{1-x}{2+x}} $$

6 step solution

Problem 70

Recall that the symbol \(\overline{z}\) represents the complex con- jugate of \(z .\) If \(z=a+b i\) and \(w=c+d i,\) prove each statement. $$ \overline{\overline{z}}=z $$

4 step solution

Problem 70

Buying a Cottage A group of friends decides to buy a vacation home for \(\$ 120,000,\) sharing the cost equally. If they can find one more person to join them, each person's contribution will drop by \(\$ 6000\) . How many people are in the group?

7 step solution

Problem 70

Solve the equation for \(x\). \(b^{2} x^{2}-5 b x+4=0 \quad(b \neq 0)\)

6 step solution

Problem 70

\(47-70\) The given equation involves a power of the variable. Find all real solutions of the equation. $$ 6 x^{2 / 3}-216=0 $$

4 step solution

Problem 71

Solve the inequality for \(x,\) assuming that \(a, b,\) and \(c\) are positive constants. (a) \(a(b x-c) \geq b c \quad\) (b) \(a \leq b x+c<2 a\)

6 step solution

Problem 71

Recall that the symbol \(\overline{z}\) represents the complex con- jugate of \(z .\) If \(z=a+b i\) and \(w=c+d i,\) prove each statement. \(z+\overline{z}\) is a real number

5 step solution

Problem 71

Solve the equation for \(x\). \(a x^{2}-(2 a+1) x+(a+1)=0 \quad(a \neq 0)\)

5 step solution

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