Types of Continuity and Discontinuity Math Example 1

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Example 1

easy
Classify the discontinuity of f(x)=x2โˆ’4xโˆ’2f(x) = \dfrac{x^2 - 4}{x - 2} at x=2x = 2.

Solution

  1. 1
    At x=2x=2: denominator =0= 0, so f(2)f(2) is undefined.
  2. 2
    Simplify (for xโ‰ 2x \neq 2): (xโˆ’2)(x+2)xโˆ’2=x+2\frac{(x-2)(x+2)}{x-2} = x+2.
  3. 3
    Limit: limโกxโ†’2(x+2)=4\lim_{x\to 2}(x+2) = 4. The limit exists.
  4. 4
    Since the limit exists but f(2)f(2) is undefined, this is a removable discontinuity (hole at (2,4)(2,4)).

Answer

Removable discontinuity at x=2x = 2 (hole at the point (2,4)(2, 4)).
A removable discontinuity occurs when the two-sided limit exists but doesn't equal the function value (or the function is undefined there). It can be 'removed' by defining f(2)=4f(2) = 4.

About Types of Continuity and Discontinuity

Continuity types classify how a function can fail to be continuous at a point. A removable discontinuity (hole) occurs when the limit exists but doesn't equal f(a). A jump discontinuity occurs when left and right limits differ. An infinite discontinuity occurs when the function approaches ยฑโˆž.

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