L'Hospitals Rule

layd33foxx

New member
Joined
Sep 24, 2011
Messages
26
Evaluate the limit using L'Hospitals Rule

lim x->0+ (x)x/2
 

Attachments

  • VIII.png
    VIII.png
    3.4 KB · Views: 23
\(\displaystyle \displaystyle \lim_{x\to 0^+} x^{x/2} = \exp\left(\frac{1}{2}\lim_{x\to 0^+}\frac{\ln(x)}{\frac{1}{x}}\right) \)
 
In other words, to find the limit of \(\displaystyle y= x^{x/2}\), start by finding the limit of \(\displaystyle y= ln(x^{x/2})= \frac{1}{2}x ln(x)\). That is of the form "\(\displaystyle 0\cdot\infty\)" which we can the write as \(\displaystyle \frac{1}{2}\frac{ln(x)}{1/x}\), of the form "\(\displaystyle \infty/\infty\)" to which L'Hopital's rule can be applied.

Because the expontial is continuous, after you have found the limit of ln(y) as, say, L, the limit of of the orginal function, \(\displaystyle x^{x/2}\) is \(\displaystyle e^L\).
 
Last edited:
Top