Math Problem Statement

Consider the function f(x) = |x + 1| / x. (a) Fill in the following table of values. (b) Are there any values of x that cannot be inputted into f? Explain. (c) Sketch a graph of f(x).

Solution

Let's go through the problem step by step.

The function given is:

f(x)=x+1xf(x) = \frac{|x+1|}{x}

Part (a): Fill in the table of values.

To compute f(x)f(x) for different values of xx, we calculate f(x)=x+1xf(x) = \frac{|x+1|}{x} for each xx in the table. The student has already attempted filling out the table. Let's verify:

For each xx:

  1. x=5x = -5: f(5)=(5)+15=45=45=0.8f(-5) = \frac{|(-5)+1|}{-5} = \frac{|-4|}{-5} = \frac{4}{-5} = -0.8 So, f(5)=0.8f(-5) = -0.8.

  2. x=4x = -4: f(4)=(4)+14=34=34=0.75f(-4) = \frac{|(-4)+1|}{-4} = \frac{|-3|}{-4} = \frac{3}{-4} = -0.75 So, f(4)=0.75f(-4) = -0.75.

  3. x=3x = -3: f(3)=(3)+13=23=230.67f(-3) = \frac{|(-3)+1|}{-3} = \frac{|-2|}{-3} = \frac{2}{-3} \approx -0.67 The student wrote 0.66-0.66, which is an approximation. So, f(3)0.67f(-3) \approx -0.67.

  4. x=2x = -2: f(2)=(2)+12=12=12=0.5f(-2) = \frac{|(-2)+1|}{-2} = \frac{|-1|}{-2} = \frac{1}{-2} = -0.5 So, f(2)=0.5f(-2) = -0.5.

  5. x=1x = -1: f(1)=(1)+11=01=0f(-1) = \frac{|(-1)+1|}{-1} = \frac{|0|}{-1} = 0 So, f(1)=0f(-1) = 0.

  6. x=1x = 1: f(1)=1+11=21=2f(1) = \frac{|1+1|}{1} = \frac{2}{1} = 2 The student wrote 22, so that's correct.

  7. x=2x = 2: f(2)=2+12=32=1.5f(2) = \frac{|2+1|}{2} = \frac{3}{2} = 1.5 So, f(2)=1.5f(2) = 1.5.

  8. x=3x = 3: f(3)=3+13=431.33f(3) = \frac{|3+1|}{3} = \frac{4}{3} \approx 1.33 So, f(3)1.33f(3) \approx 1.33.

  9. x=4x = 4: f(4)=4+14=54=1.25f(4) = \frac{|4+1|}{4} = \frac{5}{4} = 1.25 The student wrote 1.251.25, which is correct.

  10. x=5x = 5: f(5)=5+15=65=1.2f(5) = \frac{|5+1|}{5} = \frac{6}{5} = 1.2 So, f(5)=1.2f(5) = 1.2.

Part (b): Are there any values of xx that cannot be inputted into f(x)f(x)?

Yes, x=0x = 0 cannot be inputted into the function because it would result in division by zero. The expression x+1x\frac{|x+1|}{x} is undefined when x=0x = 0.

Part (c): Sketch a graph of f(x)f(x).

The graph of f(x)=x+1xf(x) = \frac{|x+1|}{x} can be sketched based on the following observations:

  • For x>0x > 0, the function behaves like f(x)=x+1x=1+1xf(x) = \frac{x+1}{x} = 1 + \frac{1}{x}.
  • For x<0x < 0, the absolute value affects the numerator, giving f(x)=x1x=11xf(x) = \frac{-x-1}{x} = -1 - \frac{1}{x}.
  • There is a vertical asymptote at x=0x = 0 since the function is undefined there.

To sketch the graph, plot the points from the table and note the behavior of the function approaching x=0x = 0. The function increases toward ++\infty as x0+x \to 0^+, and decreases toward -\infty as x0x \to 0^-.

Would you like me to draw the graph for you or provide further details?

Relative Questions:

  1. How does the absolute value in the function affect the graph?
  2. What is the behavior of f(x)f(x) as xx \to \infty and xx \to -\infty?
  3. Why does the function have a vertical asymptote at x=0x = 0?
  4. How would the graph change if there was no absolute value?
  5. Can you determine any horizontal asymptotes for this function?

Tip:

When graphing rational functions, always check for vertical asymptotes (where the denominator is zero) and horizontal asymptotes to guide the shape of the curve.

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Algebra
Rational Functions
Absolute Value
Graphing Functions

Formulas

f(x) = |x + 1| / x

Theorems

Behavior of Rational Functions
Asymptotes of Rational Functions
Continuity and Discontinuity

Suitable Grade Level

Grades 9-12