Limit of cos(x)^(1/x) - Solution Ideas

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Homework Statement



Find the limit:

\stackrel{lim}{x\rightarrow0} cos(x)^{1/x}


The Attempt at a Solution



As my intuition says this go to infinity this one behaves kind of strange.
My idea for a solution was to use this intuition. Fail.
Second I went to do Taylor-expansion on the cos, which also came up to nothing.

How would you do it?
 
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a4swe said:

Homework Statement



Find the limit:

\stackrel{lim}{x\rightarrow0} cos(x)^{1/x}


The Attempt at a Solution



As my intuition says this go to infinity this one behaves kind of strange.
My idea for a solution was to use this intuition. Fail.
Second I went to do Taylor-expansion on the cos, which also came up to nothing.

How would you do it?

What does the numerator tend to? What does the denomiator tend to?

Also, pay attention to the sign on the denominator. What can happen?
 
Last edited:
a4swe said:

Homework Statement



Find the limit:

\stackrel{lim}{x\rightarrow0} cos(x)^{1/x}


The Attempt at a Solution



As my intuition says this go to infinity this one behaves kind of strange.
My idea for a solution was to use this intuition. Fail.
Second I went to do Taylor-expansion on the cos, which also came up to nothing.

How would you do it?

Your intuition seems to be right, why is it wrong?
If its a stupid question i apologize, I'm working on learning Calculus.
 
Is it supposed to be
\lim_{x\to 0} \cos(x)^{1/x}
or
\lim_{x\to 0} \frac{\cos(x)}{x}
 
Prove $$\int\limits_0^{\sqrt2/4}\frac{1}{\sqrt{x-x^2}}\arcsin\sqrt{\frac{(x-1)\left(x-1+x\sqrt{9-16x}\right)}{1-2x}} \, \mathrm dx = \frac{\pi^2}{8}.$$ Let $$I = \int\limits_0^{\sqrt 2 / 4}\frac{1}{\sqrt{x-x^2}}\arcsin\sqrt{\frac{(x-1)\left(x-1+x\sqrt{9-16x}\right)}{1-2x}} \, \mathrm dx. \tag{1}$$ The representation integral of ##\arcsin## is $$\arcsin u = \int\limits_{0}^{1} \frac{\mathrm dt}{\sqrt{1-t^2}}, \qquad 0 \leqslant u \leqslant 1.$$ Plugging identity above into ##(1)## with ##u...
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