test the convergence or divergence for sum of (cosnpie)/n^(3/4)
my work:
(cosnpie)/n^(3/4) is similar to pie/(n^3/4)
lim as n goes to infinity is (cosnpie)/n^(3/4)times(n^3/4)/pie equals infinity
so the series diverges by limit comparison test
is this right?