Chapter 2

Precalculus : Building Concepts and Connections · 556 exercises

Problem 56

In Exercises \(49-66,\) let \(f(x)=x^{2}+x, g(x)=\sqrt{x},\) and \(h(x)=-3 x\) Evaluate each of the following. $$(g \circ h)(-12)$$

4 step solution

Problem 56

Use a graphing utility to find all real solutions. You may need to adjust the window size manually or use the ZOOMFIT feature to get a clear graph. $$\text { Solve } \sqrt{x-1.95}-3.6=-2.5$$

4 step solution

Problem 56

Compute the zeros of the quadratic function. $$f(x)=2 x^{2}-x+8$$

3 step solution

Problem 56

Use a graphing utility to decide if the function is odd, even, or neither. $$f(x)=x^{2}-4 x+1$$

4 step solution

Problem 56

Solve the quadratic equation using any method. Find only real solutions. $$x^{2}-9=0$$

3 step solution

Problem 57

Find the vertex and axis of symmetry of the associated parabola for each quadratic function. Sketch the parabola. Find the intervals on which the function is increasing and decreasing, and find the range. $$h(x)=\frac{1}{4} x^{2}+\frac{1}{2} x-2$$

4 step solution

Problem 57

In Exercises \(49-66,\) let \(f(x)=x^{2}+x, g(x)=\sqrt{x},\) and \(h(x)=-3 x\) Evaluate each of the following. $$(f \circ g)(4)$$

3 step solution

Problem 57

Use a graphing utility to find all real solutions. You may need to adjust the window size manually or use the ZOOMFIT feature to get a clear graph. $$\text { Solve } \sqrt{0.3 x+0.95}-\sqrt{0.75 x-0.5}=-0.3$$

3 step solution

Problem 57

Compute the zeros of the quadratic function. $$f(x)=-2 x^{2}-2 x+11$$

3 step solution

Problem 57

Use a graphing utility to decide if the function is odd, even, or neither. $$f(x)=-2 x^{2}+2 x+3$$

3 step solution

Problem 57

Solve the quadratic equation using any method. Find only real solutions. $$-x^{2}+2 x=1$$

4 step solution

Problem 58

Find the vertex and axis of symmetry of the associated parabola for each quadratic function. Sketch the parabola. Find the intervals on which the function is increasing and decreasing, and find the range. $$g(x)=-\frac{1}{6} x^{2}+\frac{1}{3} x+1$$

4 step solution

Problem 58

In Exercises \(49-66,\) let \(f(x)=x^{2}+x, g(x)=\sqrt{x},\) and \(h(x)=-3 x\) Evaluate each of the following. $$(f \circ g)(9)$$

2 step solution

Problem 58

Use a graphing utility to find all real solutions. You may need to adjust the window size manually or use the ZOOMFIT feature to get a clear graph. $$\text { Solve } \sqrt{0.3 x+0.95}-\sqrt{0.75 x-0.5}=-0.3$$

3 step solution

Problem 58

Compute the zeros of the quadratic function. $$g(t)=-5 t^{2}+2 t-3$$

4 step solution

Problem 58

Solve the quadratic equation using any method. Find only real solutions. $$x^{2}-4 x=-4$$

3 step solution

Problem 58

Use a graphing utility to decide if the function is odd, even, or neither. $$f(x)=2 x^{3}-x$$

3 step solution

Problem 59

In Exercises \(49-66,\) let \(f(x)=x^{2}+x, g(x)=\sqrt{x},\) and \(h(x)=-3 x\) Evaluate each of the following. $$(g \circ f)(2)$$

3 step solution

Problem 59

Use a graphing utility to find all real solutions. You may need to adjust the window size manually or use the ZOOMFIT feature to get a clear graph. Graphically solve \(\sqrt{x+1}=x+k\) for \(k=\frac{1}{2}, 1,\) and 2 How many solutions does the equation have for each value of \(k ?\)

3 step solution

Problem 59

Compute the zeros of the quadratic function. $$h(x)=3 x^{2}+8 x-16$$

4 step solution

Problem 59

Use a graphing utility to decide if the function is odd, even, or neither. $$f(x)=(x+1)(x-2)(x+3)$$

4 step solution

Problem 59

Solve the quadratic equation using any method. Find only real solutions. $$-2 x^{2}-1=3 x$$

4 step solution

Problem 60

In Exercises \(49-66,\) let \(f(x)=x^{2}+x, g(x)=\sqrt{x},\) and \(h(x)=-3 x\) Evaluate each of the following. $$(g \circ f)(1)$$

4 step solution

Problem 60

Use a graphing utility to find all real solutions. You may need to adjust the window size manually or use the ZOOMFIT feature to get a clear graph. Graphically solve \(\sqrt{x-k}=x\) for \(k=-2,0,\) and 2 How many solutions does the equation have for each value of \(k ?\)

6 step solution

Problem 60

Compute the zeros of the quadratic function. $$f(t)=2 t^{2}+11 t+9$$

3 step solution

Problem 60

Use a graphing utility to decide if the function is odd, even, or neither. $$f(x)=x^{4}-5 x^{2}+4$$

5 step solution

Problem 60

Solve the quadratic equation using any method. Find only real solutions. $$-3 x^{2}-2=7 x$$

3 step solution

Problem 61

In Exercises \(49-66,\) let \(f(x)=x^{2}+x, g(x)=\sqrt{x},\) and \(h(x)=-3 x\) Evaluate each of the following. $$(g \circ f)(-3)$$

2 step solution

Problem 61

In this set of exercises you will use radical and rational equations to study real-world problems. Four students plan to rent a minivan for a weekend trip and share equally in the rental cost of the van. By adding two more people, each person can save \(\$ 10\) on his or her share of the cost. How much is the total rental cost of the van?

3 step solution

Problem 61

Find all solutions of the quadratic equation. Relate the solutions of the equation to the zeros of an appropriate quadratic function. $$x^{2}+2 x+3=0$$

6 step solution

Problem 61

Solve the quadratic equation using any method. Find only real solutions. $$x^{2}-2 x=9$$

3 step solution

Problem 61

Use a graphing utility to decide if the function is odd, even, or neither. $$f(x)=-x^{4}+4 x^{2}$$

3 step solution

Problem 62

In Exercises \(49-66,\) let \(f(x)=x^{2}+x, g(x)=\sqrt{x},\) and \(h(x)=-3 x\) Evaluate each of the following. $$(g \circ f)(-5)$$

2 step solution

Problem 62

In this set of exercises you will use radical and rational equations to study real-world problems. Two painters are available to paint a room. Working alone, the first painter can paint the room in 5 hours. The second painter can paint the room in 4 hours working by herself. If they work together, they can paint the room in \(t\) hours. To find \(t\), we note that in 1 hour, the first painter paints \(\frac{1}{5}\) of the room and the second painter paints \(\frac{1}{4}\) of the room. If they work together, they paint \(\frac{1}{t}\) portion of the room. The equation is thus $$\frac{1}{5}+\frac{1}{4}=\frac{1}{t}$$. Find \(t,\) the time it takes both painters to paint the room working together.

3 step solution

Problem 62

Find all solutions of the quadratic equation. Relate the solutions of the equation to the zeros of an appropriate quadratic function. $$-x^{2}+x-5=0$$

4 step solution

Problem 62

Solve the quadratic equation using any method. Find only real solutions. $$-x^{2}-3 x=1$$

5 step solution

Problem 62

Applications In this set of exercises, you will use properties of functions to study real-world problems. Demand Function The demand for a product, in thousands of units, is given by \(d(x)=\frac{100}{x},\) where \(x\) is the price of the product, \((x>0) .\) Is this an increasing or a decreasing function? Explain.

3 step solution

Problem 63

Graph each quadratic function by finding a suitable viewing window with the help of the TABLE feature of a graphing utility. Also find the vertex of the associated parabola using the graphing utility. $$y_{1}(x)=0.4 x^{2}+20$$

4 step solution

Problem 63

In Exercises \(49-66,\) let \(f(x)=x^{2}+x, g(x)=\sqrt{x},\) and \(h(x)=-3 x\) Evaluate each of the following. $$(h \circ f)(2)$$

2 step solution

Problem 63

In this set of exercises you will use radical and rational equations to study real-world problems. Two water pumps work together to fill a storage tank. If the first pump can fill the tank in 6 hours and the two pumps working together can fill the tank in 4 hours, how long would it take to fill the storage tank using just the second pump?

4 step solution

Problem 63

Find all solutions of the quadratic equation. Relate the solutions of the equation to the zeros of an appropriate quadratic function. $$-3 x^{2}+2 x-4=0$$

4 step solution

Problem 63

Solve the quadratic equation using any method. Find only real solutions. $$(x-1)(x+2)=1$$

4 step solution

Problem 63

Applications In this set of exercises, you will use properties of functions to study real-world problems. Revenue The revenue for a company is given by \(R(x)=30 x\) where \(x\) is the number of units sold in thousands. Is this an increasing or a decreasing function? Explain.

3 step solution

Problem 64

Graph each quadratic function by finding a suitable viewing window with the help of the TABLE feature of a graphing utility. Also find the vertex of the associated parabola using the graphing utility. $$g(s)=-s^{2}-15$$

3 step solution

Problem 64

In Exercises \(49-66,\) let \(f(x)=x^{2}+x, g(x)=\sqrt{x},\) and \(h(x)=-3 x\) Evaluate each of the following. $$(h \circ f)(-3)$$

3 step solution

Problem 64

Find all solutions of the quadratic equation. Relate the solutions of the equation to the zeros of an appropriate quadratic function. $$-2 x^{2}+3 x-1=0$$

4 step solution

Problem 64

Solve the quadratic equation using any method. Find only real solutions. $$(x+1)(x-2)=2$$

3 step solution

Problem 64

Applications In this set of exercises, you will use properties of functions to study real-world problems. Depreciation The value of a computer \(t\) years after purchase is given by \(v(t)=2000-300 t,\) where \(v(t)\) is in dollars. Find the average rate of change of the value of the computer on the interval [0,3] , and interpret it.

4 step solution

Problem 65

Graph each quadratic function by finding a suitable viewing window with the help of the TABLE feature of a graphing utility. Also find the vertex of the associated parabola using the graphing utility. $$h(x)=(\sqrt{2}) x^{2}+x+1$$

4 step solution

Problem 65

In Exercises \(49-66,\) let \(f(x)=x^{2}+x, g(x)=\sqrt{x},\) and \(h(x)=-3 x\) Evaluate each of the following. $$(h \circ f)\left(\frac{1}{2}\right)$$

3 step solution

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