Friday, 17 April 2015

real analysis - Find limit limxrightarrow0frac2sin(x)1x=0



can someone provide me with some hint how to evaluate this limit?
lim
Unfortunately, I can't use l'hopital's rule
I was thinking about something like that:
\lim_{x\rightarrow 0}\frac{2^{\sin(x)}-1}{x} =\\\lim_{x\rightarrow 0}\frac{\ln(e^{2^{\sin(x)}})-1}{\ln(e^x)} but there I don't see how to continue this way of thinking (of course if it is correct)



Answer



Hint:



For \sin x\ne0



\dfrac{2^{\sin x}-1}x=\dfrac{2^{\sin x}-1}{\sin x}\cdot\dfrac{\sin x}x



\implies\lim_{x\to0}\dfrac{2^{\sin x}-1}x=\lim_{x\to0}\dfrac{2^{\sin x}-1}{\sin x}\cdot\lim_{x\to0}\dfrac{\sin x}x


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