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Classify the discontinuity of w(x) at x = 5

Consider the function w(x)=1x−5w(x) = \dfrac{1}{x-5}, which is undefined at x=5x = 5.

Using the three-part definition of continuity, determine which condition(s) fail for w(x)=1x−5w(x) = \dfrac{1}{x-5} at x=5x = 5, and classify the discontinuity there as removable, jump, or infinite. State which part of the definition fails and give your classification.

Hint

Check each of the three conditions in order: is w(5)w(5) defined? Does lim⁡x→5w(x)\lim_{x\to 5} w(x) exist as a finite number? Then think about what happens to 1x−5\frac{1}{x-5} as xx approaches 55 from either side.

Step-by-step solution

First check condition 1: is w(5)w(5) defined? Since the denominator x−5x-5 becomes 00 when x=5x=5, the expression 10\frac{1}{0} is undefined, so w(5)w(5) does not exist. This already tells us ww is discontinuous at x=5x=5.

Next, examine the behavior of w(x)w(x) near x=5x=5: as x→5−x \to 5^-, x−5x-5 is a small negative number, so w(x)→−∞w(x) \to -\infty; as x→5+x\to 5^+, x−5x-5 is a small positive number, so w(x)→+∞w(x)\to +\infty. Since at least one one-sided limit is infinite (rather than approaching a finite value), lim⁡x→5w(x)\lim_{x\to5} w(x) does not exist as a real number, and this behavior corresponds to a vertical asymptote at x=5x=5. Therefore the discontinuity at x=5x=5 is classified as an infinite discontinuity (condition 1, f(a)f(a) defined, fails, and the limit fails to exist for this reason).

Which continuity condition fails first for w at x equals five

Hint
Step-by-step solution

The first condition fails: w of five is not defined, since plugging in five gives division by zero. Because this condition already fails, the function cannot be continuous at that point regardless of the other two conditions. This matches the earlier finding that w is undefined at x equals five before any limit behavior is even considered.

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