Between 0 and 2pi? So 0 and 2pi consider?

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The discussion centers on the interpretation of the term "between" in trigonometric contexts, specifically regarding the interval notation for radians from 0 to 2π. Participants agree that "between 0 and 2π" typically implies 0 ≤ x < 2π, while "strictly between" indicates 0 < x < 2π. The ambiguity in wording can lead to different interpretations, as illustrated by examples where the inclusion of endpoints affects the number of solutions for equations like sin x = 0. Clarification from instructors is recommended when encountering such ambiguities.

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Hi,

I was doing trigonometry and I came across this problem when they said "between".

If they said between 0 to 2pie radians, do they include 0 and 2pie or it is 0 < x < 2pie ?

Thanks
 
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Could be either, but it's usually 0 ≤ x < 2pi.
 


< is less than so no, but usually there will be a less than or equal to somewhere in there. PI PI PI PI PI. Not pie.

\Pi \pi
 


"Between" is somewhat ambiguous, so some people will write "strictly between" to indicate that the endpoints aren't included.
 


Gregg said:
PI PI PI PI PI. Not pie.
I like pie :-p

matttan said:
I was doing trigonometry and I came across this problem when they said "between".

If they said between 0 to 2pie radians, do they include 0 and 2pie or it is 0 < x < 2pie ?
I would state your assumptions based upon the wording of the question.
For example: My solution for this problem is based on the given condition 0&lt; x &lt; 2\pi[/tex]. <br /> <br /> If this were an exam question, I would ask the teacher/professor, to clarify their meaning.
 
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Mark44 said:
"Between" is somewhat ambiguous, so some people will write "strictly between" to indicate that the endpoints aren't included.

Ouabache said:
I like pie :-p

I would state your assumptions based upon the wording of the question.
For example: My solution for this problem is based on the given condition 0&lt; x &lt; 2\pi[/tex]. <br /> <br /> If this were an exam question, I would ask the teacher/professor, to clarify their meaning.
<br /> <br /> Thanks for all the reply (:<br /> <br /> Refer: <a href="http://mathworld.wolfram.com/Between.html" target="_blank" class="link link--external" rel="nofollow ugc noopener">http://mathworld.wolfram.com/Between.html</a><br /> &quot; All points on a line segment excluding the endpoints lie between the endpoints. &quot;<br /> <br /> So I guess Between 0 and 2Pi means 0 &lt; x &lt; 2Pi?<br /> <br /> Because the author is confusing me as for the 1st example, the question states between 0 and 2pi and in his solution he writes 0 &lt; x &lt; 2Pi. And the other qs(example 2). which also says between 0 and 2pi but he writes as 0 &lt;= x &lt;= 2Pi in his solution? Is the author 1st example the correct one? <br /> <br /> Lets say if a qs states find all the possible solutions/angle for Sin x = 0 where x is between 0 and 2Pi so if example 1 came in, there will be only 1 solutions which is 1Pi as 0 and 2Pi is out of the range 0 &lt; x &lt; 2Pi. But is example 2 is used, then there will be 3 solutions which is 0, 1Pi and 2Pi as the range is 0 &lt;= x &lt;= 2Pi.
 
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I've always thought that the word "between" meant < or > (unless it said inclusive), while "from...to" had the equal sign below the > and <.
 


You are correct, the solution depends on interpretation of the given information.
It appears your author is not consistent with the use of "between" in that context.
If you have the opportunity, I would ask your teacher to clarify this sort of ambiguity
before solving your problems. If not, then state your assumptions (as you interpret the question),
and solve the problem based on those assumptions.

matttan said:
Is the author 1st example the correct one?
 

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