Math Problem Statement

Find the domain of the function f(x) = (x^2 - x)/x, prove that for all x in the domain f(x) = x - 1, and compute the limit of f(x) as x approaches 1.

Solution

Let's analyze and solve the given mathematical problem from your image.

We have the function f(x)=x2xxf(x) = \frac{x^2 - x}{x}.

Part (a): Domain of f(x)f(x)

To find the domain, we need to identify any values of xx that would make the function undefined. The function is a rational expression, and it is undefined when the denominator is 0.

Since the denominator is xx, the function is undefined at x=0x = 0.

Domain of f(x)f(x): A=R{0}A = \mathbb{R} \setminus \{0\} This means the domain is all real numbers except x=0x = 0.

Part (b): Proof that f(x)=x1f(x) = x - 1 for all xAx \in A

We simplify the function: f(x)=x2xx=x(x1)x.f(x) = \frac{x^2 - x}{x} = \frac{x(x - 1)}{x}. For x0x \neq 0, we can cancel out xx from the numerator and denominator: f(x)=x1.f(x) = x - 1. Thus, for all xAx \in A, f(x)=x1f(x) = x - 1, as required.

Part (c): Compute limx1f(x)\lim_{x \to 1} f(x)

We need to find the limit of f(x)f(x) as xx approaches 1. From part (b), we know that f(x)=x1f(x) = x - 1, so: limx1f(x)=limx1(x1).\lim_{x \to 1} f(x) = \lim_{x \to 1} (x - 1). Substituting x=1x = 1 into the expression: limx1(x1)=11=0.\lim_{x \to 1} (x - 1) = 1 - 1 = 0. Thus, the limit is: limx1f(x)=0.\lim_{x \to 1} f(x) = 0.

Summary of Answers:

  • (a): The domain is A=R{0}A = \mathbb{R} \setminus \{0\}.
  • (b): f(x)=x1f(x) = x - 1 for all xAx \in A.
  • (c): limx1f(x)=0\lim_{x \to 1} f(x) = 0.

Would you like more details on any of the steps or have any questions?


Here are 5 related questions to explore further:

  1. How would the domain change if the denominator was x+2x + 2 instead of xx?
  2. How can you verify the limit limx1f(x)\lim_{x \to 1} f(x) graphically?
  3. What is the significance of removable discontinuities in rational functions like this one?
  4. How do you handle limits when the function involves more complex expressions like trigonometric or exponential terms?
  5. Can you compute the limit limx0f(x)\lim_{x \to 0} f(x) for the given function?

Tip: Always check for values of xx that make the denominator zero when finding the domain of a rational function.

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Math Problem Analysis

Mathematical Concepts

Algebra
Rational Functions
Limits

Formulas

f(x) = (x^2 - x) / x
f(x) = x - 1 for all x ≠ 0
lim_{x → 1} (x - 1)

Theorems

Limit Theorem
Simplification of Rational Functions

Suitable Grade Level

Grades 10-12