Question

∑(3n/√(n^3-1) use ratio test to find weather series convergent or divergent ?

Answer 1

the ratio test is when you take :

an + 1 / an

for you condition :

\[ an= 3n/ \sqrt{n^3-1}\]

so:

\[an + 1/ an = (3n + 1/ \sqrt{n^3-1 +1} )/( 3n/\sqrt{n^3-1})\]

simplify ^_^

Answer 2

then take the limit as x approaches infinity :)

Answer 3

(n-1)^3 is not equal to n^3-1^3 just review your solution