Specifying vertical asymptotes in periodic functions in set notation

AI Thread Summary
The discussion focuses on the correct set notation for specifying vertical asymptotes in periodic functions. A user proposes the notation { x: x ∈ R, x ≠ n⋅(pi/2)+(pi/4) }, which is confirmed as correct for excluding vertical asymptotes at intervals of pi/2. Participants highlight that this notation effectively excludes specific asymptotes like π/4, 3π/4, and -π/4. Additionally, there are suggestions to enhance clarity using LaTeX for mathematical symbols. The conversation emphasizes the importance of precise notation in defining the domain of periodic functions with vertical asymptotes.
SubZer0
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Homework Statement
What is the general format for specifying recurring vertical asymptotes in periodic functions in set notation?
Relevant Equations
-2pi < x < 2pi
Hi all,

What is the general set notation for specifying a vertical asymptote and domain for a periodic function? For example, if I have a periodic function which has a period of pi/2, and within that period, a vertical asymptote occurs at pi/4. The domain is R, excluding that vertical asymptote. I am presuming that I can specify it something like:

{ x: x ∈ R, x ≠ n⋅(pi/2)+(pi/4) }, where n is an integer.

Does this look correct, or completely off?

Thanks!
 
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SubZer0 said:
Hi all,

What is the general set notation for specifying a vertical asymptote and domain for a periodic function? For example, if I have a periodic function which has a period of pi/2, and within that period, a vertical asymptote occurs at pi/4. The domain is R, excluding that vertical asymptote. I am presuming that I can specify it something like:

{ x: x ∈ R, x ≠ n⋅(pi/2)+(pi/4) }, where n is an integer.

Does this look correct, or completely off?

Thanks!
Looks OK to me. An example of a function with this behavior is ##f(x) = \tan(2x)##
 
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SubZer0 said:
Hi all,

What is the general set notation for specifying a vertical asymptote and domain for a periodic function? For example, if I have a periodic function which has a period of pi/2, and within that period, a vertical asymptote occurs at pi/4. The domain is R, excluding that vertical asymptote. I am presuming that I can specify it something like:

{ x: x ∈ R, x ≠ n⋅(pi/2)+(pi/4) }, where n is an integer.

Does this look correct, or completely off?

Thanks!
Let's check it out.
If n=0, then you are excluding π/4 from the domain. That's good.

If n=1, then you are excluding 3π/4 from the domain. That's good.

If n = −1, then you are excluding −π/4 from the domain. That's good.

Etc.

I'm curious about the inequality, −2pi < x < 2pi , that you have in the Relevant Equations .

Also, you can find many symbols by clicking on the icon 3rd from the right in the light blue banner at the top of the "Reply/Post thread" box.

242415

Using that, your result of
{ x: x ∈ R, x ≠ n⋅(pi/2)+(pi/4) }
becomes:
{ x: x ∈ ℝ, x ≠ n⋅(π/2)+(π/4) }

Even better, use LaTeX.
 
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Thanks, Mark44 and SammyS for your responses. Have taken on board your advice for the symbols for future posts, SammyS.
 
Since ##px^9+q## is the factor, then ##x^9=\frac{-q}{p}## will be one of the roots. Let ##f(x)=27x^{18}+bx^9+70##, then: $$27\left(\frac{-q}{p}\right)^2+b\left(\frac{-q}{p}\right)+70=0$$ $$b=27 \frac{q}{p}+70 \frac{p}{q}$$ $$b=\frac{27q^2+70p^2}{pq}$$ From this expression, it looks like there is no greatest value of ##b## because increasing the value of ##p## and ##q## will also increase the value of ##b##. How to find the greatest value of ##b##? Thanks
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