Limit of e to the tangent of x

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Discussion Overview

The discussion revolves around the limit of the expression \( e^{\tan(x)} \) as \( x \) approaches \( \frac{\pi}{2} \) from the right. Participants explore the behavior of the tangent function near this point and its implications for the limit of the exponential function.

Discussion Character

  • Mathematical reasoning
  • Exploratory
  • Technical explanation

Main Points Raised

  • One participant initiates the discussion by questioning how to approach the limit of \( e^{\tan(x)} \) as \( x \) approaches \( \frac{\pi}{2}^{+} \).
  • Another participant suggests first considering the limit of \( \tan(x) \) as \( x \) approaches \( \frac{\pi}{2}^{+} \).
  • Participants note that \( \tan(\frac{\pi}{2}) \) approaches \( -\infty \) from the right side, prompting further inquiry into the behavior of \( e \) raised to this power.
  • It is proposed that since \( \lim_{x\to-\infty} e^x = 0 \), the limit of \( e^{\tan(x)} \) as \( x \) approaches \( \frac{\pi}{2}^{+} \) would also be 0.
  • Another participant reinforces this by stating that \( e^{\tan(x)} \) can be expressed as \( \frac{1}{e^{|\tan(x)|}} \) over the interval \( \left(\frac{\pi}{2}, \pi\right] \), leading to the same conclusion of the limit being 0.
  • There is a mention of the graphical behavior of the tangent function as it approaches \( \frac{\pi}{2} \), indicating that it tends to \( -\infty \) and thus supports the conclusion regarding the limit of the exponential function.

Areas of Agreement / Disagreement

Participants generally agree that the limit of \( e^{\tan(x)} \) as \( x \) approaches \( \frac{\pi}{2}^{+} \) is 0, based on the behavior of the tangent function. However, the discussion includes various approaches and confirmations of this conclusion without explicit consensus on the method of derivation.

Contextual Notes

Some participants provide additional insights into the graphical representation of the tangent function and its limits, which may not be fully explored or resolved in the discussion.

thereidisanceman
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lim {e}^{tan(x)}
x\implies\{(pi/2)}^{+}

How do I start? Do I plug in and if so what next?
 
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I would first consider what we get for:

$$\lim_{x\to\frac{\pi}{2}^{+}}\tan(x)$$

What is the value of the above limit?
 
tan (\pi/2)
 
thereidisanceman said:
tan (\pi/2)

Think of the graph of:

$$y=\tan(x)$$

Where is the curve going as we approach $$x=\frac{\pi}{2}$$ from the right side?
 
oh, -\infty from the right
 
thereidisanceman said:
oh, -\infty from the right

Yes, and so what is $e$ raised to this power?

Note: to get your $\LaTeX$ code to parse correctly, wrap it in the MATH tags. Click the $$\sum$$ button on our toolbar, and then place your code in between the generated tags. :D
 
0?

$$\sin\left({\lim_{{}\to{a}}}\right)$$
(not related)
 
Yes, because:

$$\lim_{x\to-\infty}e^x=0$$ :D
 
Oh coolio, thanks!
 
  • #10
Also, if you right-click on any correctly displaying $\LaTeX$ math, choose Show Math As -> TeX Commands, you will see what someone typed into get a particular output. You can also use single-dollar signs to enclose displayed math, like this: $\int_{-\infty}^{\infty}e^{-x^2} \, dx=\sqrt{\pi}$, which I typed up using

Code:
$\int_{-\infty}^{\infty}e^{-x^2} \, dx=\sqrt{\pi}$,

or you can use double-dollar signs to get a displayed equation like this:

$$\int_{-\infty}^{\infty}e^{-x^2} \, dx=\sqrt{\pi},$$ which I typed up using

Code:
$$\int_{-\infty}^{\infty}e^{-x^2} \, dx=\sqrt{\pi}.$$

Notice the difference in size of the various symbols.
 
  • #11
$$\lim_{x\to\frac{\pi}{2}^+}e^{\tan(x)}$$Over the interval $\left(\frac{\pi}{2},\pi\right]$ we have $e^{\tan(x)}=\frac{1}{e^{|\tan(x)|}}$, hence$$\lim_{x\to\frac{\pi}{2}^+}e^{\tan(x)}=\lim_{x\to\frac{\pi}{2}^+}\frac{1}{e^{|\tan(x)|}}=0$$
 
  • #12
Also , you can see the graph of the function where (tanx = - infinity) when it approaches n(pi/2) or -n(pi\2), therefore the function will go to zero.
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