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Classify the discontinuity of g(x) at x = 2

Consider the function g(x)=x2+x−6x−2.g(x) = \dfrac{x^2 + x - 6}{x - 2}. Note that gg is undefined at x=2x = 2.

Determine the type of discontinuity that g(x)=x2+x−6x−2g(x) = \dfrac{x^2+x-6}{x-2} has at x=2x = 2, and find the coordinates of the point (the "hole") that would need to be filled in to make gg continuous there. State the type of discontinuity (removable, jump, or infinite) and give the hole's location as an ordered pair.

Hint

Try factoring the numerator to see if a common factor cancels with the denominator. Then check whether the resulting simplified function has a limit as x→2x \to 2.

Step-by-step solution

Factor the numerator: x2+x−6=(x−2)(x+3)x^2 + x - 6 = (x-2)(x+3). So for x≠2x \neq 2, g(x)=(x−2)(x+3)x−2=x+3.g(x) = \frac{(x-2)(x+3)}{x-2} = x+3. This cancellation is only valid where x≠2x \neq 2, since g(2)g(2) is undefined (division by zero).

Since lim⁡x→2g(x)=lim⁡x→2(x+3)=5\lim_{x\to 2} g(x) = \lim_{x\to 2}(x+3) = 5 exists but g(2)g(2) is not defined, the limit exists but is not equal to g(a)g(a) (in fact g(a)g(a) doesn't even exist). This means the discontinuity is removable, and the hole is located at the point (2,5)(2, 5).

Classify the discontinuity of g(x) at x = 2 — solution graph

Identifying what patches the discontinuity

Hint
Step-by-step solution

Yes. The earlier work showed the limit of g as x approaches two equals five, but g of two was originally undefined. Since a removable discontinuity occurs exactly when the limit exists but doesn't match the function's value (or the value is missing), setting g of two equal to five fills the hole and satisfies all three continuity conditions there.

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