Question

Does the series cos n /(n^3) converge or diverge?

Answer 1

n^3 would converge

Answer 2

what test would you use to prove it?

Answer 3

p test

Answer 4

I am assuming it is from 1 to infinity

Answer 5

Yes, it would be converge

Answer 6

yep! I just don't know how to prove it with a test

Answer 7

http://mathforum.org/library/drmath/view/74703.html

Answer 8

start with just 1/n^3

Answer 9

could you use the comparison test?

Answer 10

yes,

1/n^3 always converge

Answer 11

cos (x)<1

Answer 12

It does not require a paragraph of an explanation, you could either use the link I showed you for an example as they do some hardcore calculating or you can follow what modphysnoob is doing.