Math Problem Statement

Find the domain and range of the rational function y = (x + 1) / (x - 1).

Solution

The equation in the image is:

y=x+1x1y = \frac{x + 1}{x - 1}

You are asked to find the domain and range of this rational function.

Domain:

The domain of a function includes all the possible values of xx for which the function is defined. For rational functions, the function is undefined when the denominator is zero because division by zero is not allowed.

Here, the denominator is x1x - 1. To find when the function is undefined: x1=0    x=1x - 1 = 0 \implies x = 1 Thus, x=1x = 1 is not in the domain.

Domain: xRx \in \mathbb{R} except x=1x = 1. This can be written as: Domain: (,1)(1,)\text{Domain: } (-\infty, 1) \cup (1, \infty)

Range:

To find the range of the function, we consider the possible values of yy.

Start by solving for xx in terms of yy: y=x+1x1y = \frac{x + 1}{x - 1} Multiply both sides by x1x - 1: y(x1)=x+1y(x - 1) = x + 1 Expand and rearrange: yxy=x+1    yxx=y+1yx - y = x + 1 \implies yx - x = y + 1 Factor out xx: x(y1)=y+1    x=y+1y1x(y - 1) = y + 1 \implies x = \frac{y + 1}{y - 1} The function is undefined when the denominator y1=0y - 1 = 0, which occurs when y=1y = 1.

Thus, the function can take all real values of yy except y=1y = 1.

Range: yRy \in \mathbb{R} except y=1y = 1. This can be written as: Range: (,1)(1,)\text{Range: } (-\infty, 1) \cup (1, \infty)

Would you like more details or have any further questions?


Here are 5 related questions you might find interesting:

  1. How do you find the vertical and horizontal asymptotes of the function y=x+1x1y = \frac{x + 1}{x - 1}?
  2. What is the behavior of the function y=x+1x1y = \frac{x + 1}{x - 1} as xx approaches 1 from the left and right?
  3. How do you determine the intercepts of the function y=x+1x1y = \frac{x + 1}{x - 1}?
  4. Can you describe the transformations of the parent function y=1xy = \frac{1}{x} that result in y=x+1x1y = \frac{x + 1}{x - 1}?
  5. How would you sketch the graph of y=x+1x1y = \frac{x + 1}{x - 1} based on the domain, range, and asymptotes?

Tip: When finding the range of a rational function, solving for xx in terms of yy can often help identify the values that yy cannot take.

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Math Problem Analysis

Mathematical Concepts

Algebra
Rational Functions
Domain and Range

Formulas

y = (x + 1) / (x - 1)

Theorems

Definition of Domain and Range of Functions

Suitable Grade Level

Grades 9-10