How to represent this absolute value inequality with constants?

AI Thread Summary
The discussion focuses on how to represent an absolute value inequality involving a constant "a" on an x-graph. Participants clarify that "a" does not need to be separated into different cases, as the inequality can be represented by a single interval, specifically (a - δ, a + δ). The importance of showing the points a - δ and a + δ on the graph is emphasized, while the point x = 0 is deemed irrelevant. To indicate that x = a is excluded from the interval, round brackets are suggested for notation. Overall, the focus remains on simplifying the representation of the inequality without complicating it with unnecessary cases.
kenny1999
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Homework Statement
absolute value
Relevant Equations
inequality
see attached image, it asks to repesent it in x-graph
constant "a" isn't conditioned.
Do I need to separate it into a few cases of the constant a and represent each in one x-graph?
Screenshot 2021-03-09 140649.png
 
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What do you mean by an x-graph? Do you mean on the x-axis?
 
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You should read that the formula means x is around a within distance ##\epsilon##.
 
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PeroK said:
What do you mean by an x-graph? Do you mean on the x-axis?

yes. Sorry I am not in English language
 
anuttarasammyak said:
You should read that the formula means x is around a within distance ##\epsilon##.

a isn't conditioned, e.g. >0 or <0

so do I need to separate into a few cases and draw the graph??
 
OK . This is what I have done, I don't know if I am correct. I am teaching my cousin, but I have left school for 20 years
12231231313131.jpg
 
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Another question , I avoid starting a new topic. Am I correct??
66.jpg
 
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kenny1999 said:
OK . This is what I have done, I don't know if I am correct. I am teaching my cousin, but I have left school for 20 years
I think all you need to do is show one interval ##(a - \delta, a + \delta)##. You don't need all those different cases. The point ##x = 0## is not important here.
 
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kenny1999 said:
Another question , I avoid starting a new topic. Am I correct??
I guess that's ##0 < |x - a| < \delta##?
 
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To make your diagram more clear, show ##a## on it. Then show ##a-\delta## and ##a+\delta##. There is no reason to even show where anything else, like ##x=0##, is. Then one diagram takes care of all the cases.
 
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PeroK said:
I think all you need to do is show one interval ##(a - \delta, a + \delta)##. You don't need all those different cases. The point ##x = 0## is not important here.

Hi, did you mean I do not have to consider the possible ranges of value of a ? (Since a isn't conditioned but the delta is given that >0, that's why I am wondering if I need to separate a into different ranges of value
 
  • #12
PeroK said:
I guess that's ##0 < |x - a| < \delta##?
No, "Another question" is really another, not related to the first question, yes the first question was ##0 < |x - a| < \delta##

I think the second question does NOT include x=0. How to draw a symbol to represent that x=0 isn't included?? an arrow??
 
  • #13
kenny1999 said:
Hi, did you mean I do not have to consider the possible ranges of value of a ? (Since a isn't conditioned but the delta is given that >0, that's why I am wondering if I need to separate a into different ranges of value
You don't have to consider different values for ##a##.
 
  • #14
kenny1999 said:
No, "Another question" is really another, not related to the first question, yes the first question was ##0 < |x - a| < \delta##

I think the second question does NOT include x=0. How to draw a symbol to represent that x=0 isn't included?? an arrow??
It's ##x =a## that is excluded. I would just use ##(a-\delta, a)(a, a + \delta)## with round brackets to show the end points are excluded.
 
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