How do I evaluate the following using L'Hopitals Rule?

Question

lim(n->0) of [1-cos(n)]/n^2

Please help, really stuck!!!!

Answer 1

For indertiminable ratios like your one, you differentiate both parts seperatly to get (sin(n))/2n
another indeterminable ratio at you limit, so just differentiate them again then go to the limit and you get you answer =1/2

Answer 2

=limsin (n)/2n and as sin(n)/n =>0 as n=>0 the limit is 1/2