I found this problem interesting to be here:
If $a,b>0$ then find the following limit: $$\lim_{x\to\pm\infty}\left(\frac{a^{\frac{1}{x}}+b^{\frac{1}{x}}}{2}\right)^x$$
Thanks!
I found this problem interesting to be here:
If $a,b>0$ then find the following limit: $$\lim_{x\to\pm\infty}\left(\frac{a^{\frac{1}{x}}+b^{\frac{1}{x}}}{2}\right)^x$$
Thanks!
One can use L'Hospital's Rule mechanically. The logarithm of our expression is $$\frac{\log\left(\frac{a^{1/x}+b^{1/x}}{2}\right)}{1/x}.$$ Differentiate top and bottom. We get $$\frac{1}{\frac{a^{1/x}+b^{1/x}}{2}}(-1/x^2)\frac{\frac{a^{1/x}\log a+b^{1/x}\log b}{2}}{(-1/x^2)}$$ Cancel the $(-1/x^2)$. The limit is $\dfrac{\log a+\log b}{2}$. Then exponentiate.