Uh oh! Wolfram|Alpha doesn't run without JavaScript.
Please enable JavaScript. If you don't know how, you can find instructions
here
.
Once you've done that, refresh this page to start using Wolfram|Alpha.
f(x) = ln x ——定义域？何处连续？
f(x) = ln x ——定义域？何处连续？
Natural Language
Math Input
Extended Keyboard
