Why Does the Limit of |x+4|/x+4 Equal 4 as x Approaches -4 from the Right?

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SUMMARY

The limit of the function f(x) = 4 |x + 4| / (x + 4) as x approaches -4 from the right is definitively 4. When x is greater than -4, the absolute value |x + 4| simplifies to x + 4, allowing the limit to be computed as lim_{x → -4^+} f(x) = lim_{x → -4^+} 4(x + 4)/(x + 4) = 4. The reasoning behind this conclusion is that the absolute value of x + 4 remains positive and equals 4 as x approaches -4 from the right, confirming that the limit is indeed 4.

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buffgilville
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Compute the limit of: (absolute value)

f(x) = 4 (absolute value of x + 4) / (x+4)

as x approaches -4 from the right.

I got 4 because x>-4. Am I right?
 
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Yep that's correct! When [tex]x > 4, |x + 4| = x + 4[/tex]
Thus,

[tex]lim_{x \rightarrow -4^+} f(x) = lim_{x \rightarrow -4^+} 4\frac{x+4}{x+4} = 4[/tex]
 


Your answer is partially correct. The limit of the given function as x approaches -4 from the right is indeed 4. However, your reasoning is not entirely accurate. The reason why the limit is 4 is not because x is greater than -4, but rather because the absolute value of x+4 is always equal to 4 when x is approaching -4 from the right. This is because when x is approaching -4 from the right, it means that x is getting closer and closer to -4, but never actually reaches -4. And since the absolute value of a number is always positive, no matter how close x gets to -4, the absolute value of x+4 will always be 4. Therefore, the limit of the function is 4.
 

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