Solving a Trigonometric Limit Problem

Click For Summary

Homework Help Overview

The discussion revolves around evaluating a limit involving trigonometric functions, specifically the limit of the difference of tangent functions as one variable approaches another. The problem is situated within the context of trigonometric limits and their properties.

Discussion Character

  • Exploratory, Mathematical reasoning, Assumption checking

Approaches and Questions Raised

  • Participants explore the conversion of the limit expression into a recognizable form, particularly relating it to the tangent subtraction formula. There are attempts to manipulate the denominator through distributivity and factoring. Questions arise regarding alternative representations of the denominator.

Discussion Status

Some participants have offered guidance on manipulating the expression, while others have noted their realizations about the limit's structure. The discussion reflects a collaborative effort to clarify the problem without reaching a definitive conclusion.

Contextual Notes

There appears to be some confusion regarding the additional terms in the denominator and how they affect the limit's evaluation. Participants are navigating the constraints of the problem as they work through their reasoning.

terryds
Messages
392
Reaction score
13

Homework Statement



##\lim_{a\rightarrow b} \frac{tan\ a - tan\ b}{1+(1-\frac{a}{b})\ tan\ a\ tan\ b - \frac{a}{b}}## = ...

Homework Equations



tan (a - b) = (tan a - tan b)/(1+tan a tan b)

The Attempt at a Solution


[/B]
I don't know how to convert it to the form of tan (a-b) since there are some extras in the denominator
Please help
 
Physics news on Phys.org
Use distributivity in the denominator and then factor it .
 
Looking only at the denominator, can you write it in another way?
 
Math_QED said:
Use distributivity in the denominator and then factor it .
robphy said:
Looking only at the denominator, can you write it in another way?

Alright, I've just noticed it...

##lim_{a->b}\frac{tan\ a - tan\ b}{(1-\frac{a}{b})(1+tan\ a\ tan\ b)} = lim_{a->b}\frac{tan (a-b)}{(\frac{b-a}{b})} = -b##

Thanks for help!
 
terryds said:
Alright, I've just noticed it...

##lim_{a->b}\frac{tan\ a - tan\ b}{(1-\frac{a}{b})(1+tan\ a\ tan\ b)} = lim_{a->b}\frac{tan (a-b)}{(\frac{b-a}{b})} = -b##

Thanks for help!

Very well!
 

Similar threads

  • · Replies 8 ·
Replies
8
Views
2K
  • · Replies 7 ·
Replies
7
Views
3K
Replies
15
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
Replies
5
Views
2K
  • · Replies 15 ·
Replies
15
Views
4K
  • · Replies 8 ·
Replies
8
Views
2K
  • · Replies 6 ·
Replies
6
Views
3K
Replies
12
Views
3K
  • · Replies 4 ·
Replies
4
Views
2K