Question

Find the limit involving absolute value and a squared term

Original question: g) $\lim_{x\to -2}\frac{(x+2)^2}{|x+2|}$

Expert Verified Solution

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Expert intro: This one is all about sign. The absolute value changes the algebra depending on which side of the point you approach from, so the shortcut is to split the expression first.

Detailed walkthrough

We want

limx2(x+2)2x+2.\lim_{x\to -2}\frac{(x+2)^2}{|x+2|}.

Step 1: Simplify the quotient

For x2x\neq -2,

(x+2)2x+2=x+2.\frac{(x+2)^2}{|x+2|}=|x+2|.

Why? Because (x+2)2=(x+2)2(x+2)^2=(|x+2|)^2.

Step 2: Take the limit

So the problem becomes

limx2x+2.\lim_{x\to -2}|x+2|.

As x2x\to -2, we have x+20x+2\to 0, hence

x+20.|x+2|\to 0.

Step 3: Final result

0.\boxed{0}.

💡 Pitfall guide

A classic mistake is splitting into cases too late and overcomplicating the algebra. Another is saying the limit does not exist because of the absolute value. Here the absolute value is harmless: after simplification, both sides go to 0.

🔄 Real-world variant

If the numerator were just x+2x+2 instead of (x+2)2(x+2)^2, then

x+2x+2\frac{x+2}{|x+2|}

would approach 11 from the right and 1-1 from the left, so the limit would fail to exist. The extra square is what removes the sign problem.

🔍 Related terms

absolute value, two-sided limit, sign analysis

FAQ

What is the limit of (x+2)^2 over |x+2| as x approaches -2?

The limit is 0 because the expression simplifies to |x+2| for x not equal to -2.

Does the absolute value cause the limit to fail to exist?

No. After simplification, both sides approach 0, so the two-sided limit exists.

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