Verifying the Correctness of Your Answer

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The discussion revolves around verifying the correctness of a mathematical answer, specifically regarding the use of "OR" instead of "AND" when describing intervals. It clarifies that "AND" corresponds to intersection (∩) while "OR" corresponds to union (∪), which is necessary for the intervals given. There is also a mention of a potential asymptote at x = -6, suggesting that the function may not be defined in that range. Additionally, the omission of the interval (6,7] is highlighted, indicating it should also be included in the increasing function description. Accurate notation and interval representation are emphasized for clarity in mathematical communication.
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Homework Statement
Given the following graph, what are the intervals where the function is increasing, decreasing, or constant?
Relevant Equations
n/a
Screen Shot 2020-05-28 at 12.47.36 PM.png

Screen Shot 2020-05-28 at 2.32.42 PM.png

Is this answer correct?
 
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I see what you mean, but you should write OR instead of AND. The word AND corresponds to ##\cap## while OR corresponds to ##\cup##, which is what you need here.

So, to be totally clear, rather write: Increasing on ##[-4,-2]\cup [4,6]## and similarly for decreasing.
 
I'm not really sure, but if in ##x=-6## there is an asymptote, then the function is not defined in ##\left(-\infty,-6\right]##
 
What happened to (6,7]?
 
haruspex said:
What happened to (6,7]?
that is also increasing.
 
angela107 said:
that is also increasing.
Sure, just pointing out that you omitted it from your answer.
 
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Question: A clock's minute hand has length 4 and its hour hand has length 3. What is the distance between the tips at the moment when it is increasing most rapidly?(Putnam Exam Question) Answer: Making assumption that both the hands moves at constant angular velocities, the answer is ## \sqrt{7} .## But don't you think this assumption is somewhat doubtful and wrong?

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