Math Problem Statement

Which of the following is/are signified by lim x->a f(x)=inf.

-The limit exists and equals infinity. -The value of f(x) becomes infinite when x approaches a. -The value of x goes out to infinity, when it gets close to a. -As x approaches, the value of f(x) increases without bound. -This means that f(a) = inf.

Solution

The expression limxaf(x)=\lim_{x \to a} f(x) = \infty indicates how the function behaves as xx approaches aa, not necessarily at aa itself. Let's evaluate each of the provided statements:

  1. The limit exists and equals infinity
    True – The statement limxaf(x)=\lim_{x \to a} f(x) = \infty signifies that the limit exists, and as xx approaches aa, the function f(x)f(x) increases without bound, which is interpreted as the limit "being" infinity.

  2. The value of f(x) becomes infinite when x approaches a
    True – This is another way of saying that as xx gets closer to aa, the values of f(x)f(x) grow arbitrarily large (in other words, go to infinity).

  3. The value of x goes out to infinity, when it gets close to a
    False – This statement is incorrect because it confuses the behavior of the function f(x)f(x) with the behavior of xx. As xax \to a, the values of xx approach aa, not infinity. It is the function f(x)f(x), not xx, that tends towards infinity.

  4. As x approaches a, the value of f(x) increases without bound
    True – This is a correct interpretation. As xx gets closer to aa, the function values increase indefinitely.

  5. This means that f(a) = ∞
    False – The statement limxaf(x)=\lim_{x \to a} f(x) = \infty says nothing about the value of f(a)f(a). The function might not even be defined at aa, and even if it is, the value of f(a)f(a) could be finite or undefined. The limit describes the behavior near aa, not at aa.

Summary:

  • True: Statements 1, 2, 4
  • False: Statements 3, 5

Would you like more details or have any questions?

Related Questions:

  1. What does it mean for a function to have a finite limit as xax \to a?
  2. How does limxaf(x)=\lim_{x \to a^-} f(x) = \infty differ from limxa+f(x)=\lim_{x \to a^+} f(x) = \infty?
  3. Can a function be defined at aa if limxaf(x)=\lim_{x \to a} f(x) = \infty?
  4. What is the difference between limits at infinity and limits approaching a finite value?
  5. How does one evaluate limits involving infinity in rational functions?

Tip: Always remember that limits describe the behavior of a function near a point, not necessarily at the point itself.

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Math Problem Analysis

Mathematical Concepts

Limits
Infinity
Behavior of Functions

Formulas

lim x->a f(x) = ∞

Theorems

Limit Theorems
Infinity Limit Theorem

Suitable Grade Level

Grades 11-12