Limit of a trigonometric thing

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Homework Help Overview

The problem involves finding the limit of a trigonometric expression as x approaches zero, specifically the limit of \( \frac{x \csc(4x)}{\cos(17x)} \).

Discussion Character

  • Exploratory, Mathematical reasoning, Assumption checking

Approaches and Questions Raised

  • Participants discuss starting with trigonometric identities and limits, particularly the relationship between sine and cosecant. There is a focus on how to manipulate the expression and what limits to apply as x approaches zero.

Discussion Status

Some participants have offered insights into using trigonometric identities and limits, while others are exploring the implications of these transformations. There is an ongoing dialogue about the correct approach to handle the denominator.

Contextual Notes

Participants express uncertainty about the initial steps and the appropriate limits to apply, indicating a need for clarification on the mathematical expressions involved.

Jan Hill
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Homework Statement


Find the limit as x approaches zero of xcsc4x = the numerator over cos17x = the denominator


Homework Equations





The Attempt at a Solution



I don't know how to start except maybe multiplying both numerator and denominator by 4
 
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This?
[tex]\lim_{x \to 0} \frac{x~csc(4x)}{cos(17x)}[/tex]

Start with some trig identities, such as csc(x) = 1/sin(x). There are some trig limits that will be helpful, such as lim sin(x)/x = 0, as x --> 0.
 
so does this become lim as x approaches 0 of x times 1/sin(4x)
and this is lim as x approaches 0 of x/sin(4x)

and what trig limit should I use to deal with the denominator?


and please accept my many thanks for your quick reply of earlier!
 
Jan Hill said:
so does this become lim as x approaches 0 of x times 1/sin(4x)
and this is lim as x approaches 0 of x/sin(4x)
That's part of it.

It would be helpful if you wrote actual mathematics equations and expressions, rather than verbose English descriptions.
Jan Hill said:
and what trig limit should I use to deal with the denominator?


and please accept my many thanks for your quick reply of earlier!
 

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