Is the Function f=tan(2x)/x Continuous at x=0?

  • Context: MHB 
  • Thread starter Thread starter cbarker1
  • Start date Start date
  • Tags Tags
    Continuous Function
Click For Summary

Discussion Overview

The discussion centers on the continuity of the function \( f = \frac{\tan(2x)}{x} \) at \( x = 0 \). Participants explore whether it is possible to define the function at this point in a way that maintains continuity, involving limit calculations and function definitions.

Discussion Character

  • Mathematical reasoning
  • Debate/contested

Main Points Raised

  • One participant proposes that the function can be defined at \( x = 0 \) such that it is continuous.
  • Another participant suggests computing the limit as \( x \) approaches 0 to determine continuity.
  • Two participants report that they computed the limit and both obtained a value of 2.
  • A proposed definition of the function is given, where \( f(x) = \frac{\tan(2x)}{x} \) for \( x \neq 0 \) and \( f(0) = 2 \), with a claim that this definition ensures continuity everywhere.

Areas of Agreement / Disagreement

Participants generally agree on the limit value of 2 as \( x \) approaches 0, but there is no consensus on the implications of this limit for the overall continuity of the function, as the discussion includes differing perspectives on defining \( f \) at \( x = 0 \).

Contextual Notes

The discussion does not resolve whether the proposed definition of the function is universally accepted as correct, and it remains unclear if all assumptions regarding continuity are fully addressed.

cbarker1
Gold Member
MHB
Messages
345
Reaction score
23
Let $f=tan(2x)/x$, x is not equal to 0.

Can the f be defined at x=0 such that it is continuous? I answered yes. I am wondering if the answer is correct. Thank you for your help

CBarker1
 
Physics news on Phys.org
Compute limit at $0$. What do you get?
 
I got 2.
 
Cbarker1 said:
I got 2.

So,
$$\lim_{x\to 0} \frac{\tan 2x}{x} = 2$$
Now define the function,
$$ f(x) = \left\{ \begin{array}{ccc}(\tan x)/x & \text{if} & x\not = 0 \\ 2 & \text{if}& x=0 \end{array} \right. $$

This function is continuous everywhere because at $0$ we have $\lim_{x\to 0}f(x) = f(0) = 2$.
 

Similar threads

  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 4 ·
Replies
4
Views
1K
  • · Replies 9 ·
Replies
9
Views
3K
  • · Replies 12 ·
Replies
12
Views
3K
  • · Replies 9 ·
Replies
9
Views
2K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 3 ·
Replies
3
Views
1K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 10 ·
Replies
10
Views
5K
  • · Replies 8 ·
Replies
8
Views
1K