I need help in three basic problems. (But unfortunatelly I can't solve them!)

1. Where is the following function convex/concave? +infection points

$\displaystyle y=\frac{1}{\ln(x)}$

2.What is the integral of the following function?

$\displaystyle f(x)=\frac{\sqrt{1+x^2}}{x}$

3.Determine the surface of revolutionif we rotate the function around the x-axis!

$\displaystyle y=e^{-x}$, $\displaystyle \left[0,\infty\right[$

Thank you very much in advance!

Happy new year!