A basic function question - with a strange absolute value placement

AI Thread Summary
The discussion centers on the function f(x) defined in three segments: x+9 for x < -3, -2x for |x| ≤ 3, and -6 for x > 32. The placement of the absolute value in the middle segment is clarified to be significant, as |x| ≤ 3 translates to the range -3 ≤ x ≤ 3. This means the function is defined for all x within that range, contrary to the initial assumption that it might be undefined between -3 and 0. The clarification emphasizes that the absolute value notation is not a distraction but an essential part of the function's definition. Understanding this equivalence resolves the confusion regarding the function's domain.
latefreight
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Homework Statement



If f(x) is equal to...

x+9 if x<-3
-2x if |x|\leq 3
-6 if x > 32. The attempt at a solution

The first and third "segments" of when the function is defined as being x+9 and -6 are pretty straightforward to me, however I am unaware of the significance of the placement of the absolute value of x in the middle if statement of when the function is equal to -2x. Is it significant at all? Does this imply this function is undefined when -3 < x < 0? Or is it, as my initial hunch was, really just some type of a distraction?
 
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|x| <= 3 is equivalent to -3 <= x <= 3, so your hunch that this is a distraction is wrong.
 
<br /> 0 \le \left| x \right| \le a \; \Leftrightarrow \; -a \le x \le a<br />
 
Thank you. I didn't choose my word "distraction" cautiously enough. Since the statements you both posted are equivalent - that was indeed what I needed to know.
 
I picked up this problem from the Schaum's series book titled "College Mathematics" by Ayres/Schmidt. It is a solved problem in the book. But what surprised me was that the solution to this problem was given in one line without any explanation. I could, therefore, not understand how the given one-line solution was reached. The one-line solution in the book says: The equation is ##x \cos{\omega} +y \sin{\omega} - 5 = 0##, ##\omega## being the parameter. From my side, the only thing I could...

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