Math Problem Statement

Determine if the Intermediate Value Theorem (IVT) applies to the following problems: 1. For a continuous function g(x), given values g(0) = 3 and g(2) = 8, does IVT guarantee a c in (0, 2) such that g(c) = 5? 2. For the function k(x) = (x^2 - x - 2) / (x^2 - 4), does IVT guarantee a c in (0, 2) such that k(c) = -4?

Solution

Let us analyze and solve the provided questions step-by-step.


Problem 1:

The table gives some function values for the continuous function g(x)g(x).
We are asked whether the Intermediate Value Theorem (IVT) applies to show that there exists some cc in the interval (0,2)(0, 2) for which g(c)=5g(c) = 5.

Given Information:

  • g(0)=3g(0) = 3
  • g(2)=8g(2) = 8

Solution:

  1. Verify continuity:
    The problem explicitly states that g(x)g(x) is continuous. This satisfies the first condition of the IVT, which requires continuity on the closed interval [0,2][0, 2].

  2. Check for g(c)=5g(c) = 5 within the interval:
    The function value g(x)g(x) changes from g(0)=3g(0) = 3 to g(2)=8g(2) = 8.
    Since g(x)g(x) is continuous, it must take on every value between 3 and 8 as xx moves from 0 to 2.
    Specifically, 55 lies in the interval [3,8][3, 8], so there must exist some c(0,2)c \in (0, 2) such that g(c)=5g(c) = 5.

Conclusion:

IVT applies.
This is because g(x)g(x) is continuous on [0,2][0, 2], and g(0)<5<g(2)g(0) < 5 < g(2).


Problem 2:

Let k(x)=x2x2x24k(x) = \frac{x^2 - x - 2}{x^2 - 4}. We are tasked with determining if there must exist some xx between 0 and 2 for which k(x)=4k(x) = -4, based on the IVT.

Given Information:

  • k(x)=x2x2x24k(x) = \frac{x^2 - x - 2}{x^2 - 4}
  • Interval: (0,2)(0, 2)

Solution:

  1. Check continuity of k(x)k(x):
    To use IVT, k(x)k(x) must be continuous on the interval (0,2)(0, 2).

    • Analyze the denominator x24x^2 - 4:
      x24=(x2)(x+2).x^2 - 4 = (x - 2)(x + 2). The denominator equals zero at x=2x = 2 and x=2x = -2.
      Thus, k(x)k(x) is not defined at x=2x = 2, meaning k(x)k(x) is not continuous on (0,2)(0, 2).
  2. Conclude based on continuity:
    Since k(x)k(x) is not continuous on (0,2)(0, 2), the IVT does not apply, and we cannot guarantee the existence of some c(0,2)c \in (0, 2) for which k(c)=4k(c) = -4.

Conclusion:

IVT does not apply.
This is because k(x)k(x) is not continuous at x=2x = 2.


Final Answer Summary:

  1. Problem 1: IVT applies because g(x)g(x) is continuous, and 55 is between g(0)=3g(0) = 3 and g(2)=8g(2) = 8.
  2. Problem 2: IVT does not apply because k(x)k(x) is not continuous at x=2x = 2.

Let me know if you'd like further clarifications or details!
Here are 5 follow-up questions for deeper understanding:

  1. What does it mean for a function to be continuous on an interval?
  2. Why is the Intermediate Value Theorem dependent on continuity?
  3. Can a function that has a removable discontinuity satisfy the IVT?
  4. How can you rewrite k(x)=x2x2x24k(x) = \frac{x^2 - x - 2}{x^2 - 4} by factoring both the numerator and denominator?
  5. What happens if we change the interval for k(x)k(x) to (0,1.9)(0, 1.9)? Does the IVT apply in this case?

Tip: Always check for continuity before applying the IVT. If a function is discontinuous on the interval, the theorem cannot guarantee intermediate values.

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Math Problem Analysis

Mathematical Concepts

Intermediate Value Theorem
Continuity of Functions
Interval Analysis

Formulas

g(c) ∈ [g(a), g(b)] if g(x) is continuous on [a, b]
k(x) = (x^2 - x - 2) / (x^2 - 4)

Theorems

Intermediate Value Theorem

Suitable Grade Level

Grades 11-12 (Advanced Placement Calculus)