Math Problem Statement

Apply the definition of continuity to identify any points of discontinuity in the function f(x) = (𝑥−2)/(𝑥^2−3𝑥+2)

Solution

To determine the points of discontinuity in the function f(x)=x2x23x+2f(x) = \frac{x - 2}{x^2 - 3x + 2}, we can use the definition of continuity, which states that a function is continuous at a point x=ax = a if the following three conditions hold:

  1. f(a)f(a) is defined.
  2. limxaf(x)\lim_{x \to a} f(x) exists.
  3. limxaf(x)=f(a)\lim_{x \to a} f(x) = f(a).

The first step is to factor the denominator x23x+2x^2 - 3x + 2.

Step 1: Factor the denominator

The quadratic in the denominator can be factored as: x23x+2=(x1)(x2).x^2 - 3x + 2 = (x - 1)(x - 2).

So the function becomes: f(x)=x2(x1)(x2).f(x) = \frac{x - 2}{(x - 1)(x - 2)}.

Step 2: Simplify the function

We notice that the numerator x2x - 2 and one factor in the denominator, x2x - 2, are the same. This means we can cancel the common factor, but we must note that this cancellation is only valid for x2x \neq 2. So the simplified function is: f(x)=1x1,forx2.f(x) = \frac{1}{x - 1}, \quad \text{for} \quad x \neq 2.

Step 3: Identify points of discontinuity

Now we analyze the points where the function is not continuous:

  • At x=2x = 2: The original function is undefined because the denominator becomes zero when x=2x = 2. Even after simplification, the function still has no definition at x=2x = 2. Thus, x=2x = 2 is a removable discontinuity, because if we redefine the function at this point, continuity could be restored.

  • At x=1x = 1: The simplified function f(x)=1x1f(x) = \frac{1}{x - 1} is undefined at x=1x = 1 because the denominator becomes zero. This creates a non-removable (infinite) discontinuity at x=1x = 1, as the limit does not exist at this point.

Conclusion

The function has two discontinuities:

  1. A removable discontinuity at x=2x = 2.
  2. A non-removable discontinuity at x=1x = 1.

Would you like further details or have any questions?

Here are some related questions to further explore this topic:

  1. What is the difference between removable and non-removable discontinuities?
  2. How can we redefine the function to remove the discontinuity at x=2x = 2?
  3. How do you determine the limits at points of discontinuity?
  4. Can a function have both types of discontinuities at the same point?
  5. How would the graph of this function look around x=1x = 1 and x=2x = 2?

Tip: To handle rational functions like this one, always check for factors that cancel out in the numerator and denominator, as they often indicate removable discontinuities.

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Math Problem Analysis

Mathematical Concepts

Calculus
Continuity
Discontinuity
Rational Functions
Factorization

Formulas

Definition of continuity: A function f is continuous at x = a if f(a) is defined, lim(x→a) f(x) exists, and lim(x→a) f(x) = f(a)

Theorems

Limit Theorem
Factorization of Quadratic Equations

Suitable Grade Level

Grades 11-12