Limit of sin2x/sin3x | Find the Solution

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The limit of sin(2x)/sin(3x) as x approaches 0 can be evaluated using the hint provided, which involves manipulating the expression into a form that utilizes the known limit of sin(x)/x. By rewriting the limit as (2 sin(2x)/(2x)) * (3x/(3 sin(3x)), the connection to the limit of sin(x)/x becomes clearer. The final answer is determined to be 2/3. The discussion highlights the importance of recognizing relationships in limits and how a simple hint can clarify complex problems. Understanding these concepts is essential for solving similar calculus problems effectively.
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Homework Statement



Determine the limit of

\lim_{x \to 0} \frac {sin2x}{sin3x}

Homework Equations



Hint: Find \lim_{x\to 0} (\frac{2 sin 2x}{2x}) (\frac{3x}{3 sin 3x})

The Attempt at a Solution



I've been blankly staring at it not knowing where to start. I think the only thing that the hint manages to do is to confuse me.

Any help on helping me to start it? I don't understand the hint.

Thanks in advance.
 
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Do you not what is \lim _{x \to 0} \frac{sin(x)}{x}?

ehild
 
In your book or notes, you should find how to evaluate
\lim_{x \to 0} \frac{\sin x}{x}
 
ehild said:
Do you not what is \lim _{x \to 0} \frac{sin(x)}{x}?

ehild

Yes they are equal to one, but they aren't asking for \lim_{x \to 0} \frac {sinx}{x}

They are asking for \lim_ {x \to 0} \frac{sin2x}{sin3x}
 
And you see absolutely no connection to that limit and the hint?
 
vela said:
And you see absolutely no connection to that limit and the hint?

Ohhhhhh !

Its funny how someone can say so little yet help so much hehe. Thanks, I got it now.
 
Answer is 2/3.
 
Nano-Passion said:
Its funny how someone can say so little yet help so much hehe. Thanks, I got it now.
I think we've all had those moments where we fail to see what in hindsight seems so obvious. :wink:
 
vela said:
I think we've all had those moments where we fail to see what in hindsight seems so obvious. :wink:

Thank you for your help by the way:)
 
  • #10
For a more "formal" look, let u= 2x so that you have
\lim_{x\to 0}\frac{sin(2x)}{2x}= \lim_{u\to 0}\frac{sin(u)}{u}
 
  • #11
HallsofIvy said:
For a more "formal" look, let u= 2x so that you have
\lim_{x\to 0}\frac{sin(2x)}{2x}= \lim_{u\to 0}\frac{sin(u)}{u}

Hey halls, thanks for the suggestion. Will keep in mind in the future. ^.^
 
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