find out whether this is divergent, c.convergent or abs convergent

$\displaystyle \sum\frac{2^{n}-4^{n}}{3^{n+1}+4^{n+1}}$

and

$\displaystyle \sum sin^{2}\frac{1}{n}$

so I've basically ruled out the c.convergence..

but i havent the slightest idea how to start the first one?

for the second I thought that 1/n is divergent, which means the the whole series would be divergent..?