I have to do this for tomorrow and I have no clue how to solve this problem:

For what functions f(x) and g(x) below, will the $\displaystyle \lim_{x\rightarrow \infty} \frac{f(x)}{g(x)}=0$?

a) $\displaystyle f(x)=e^x, g(x) = x^2$

b) $\displaystyle f(x)=e^x, g(x)=ln (x)$

c) $\displaystyle f(x)=ln (x), g(x)=e^x$

d) $\displaystyle f(x)=x, g(x)=ln (x)$

e) $\displaystyle f(x)=3^x, g(x)=2^x$

Thanks