Question

How can I fin thelimit for + infinity of n*sin(1/n)*cos (1/n^2) ?

Answer 1

put n = 1/x in the function.
1/n = ... ?
1/n^2 = ... ?

Answer 2

if I do that I'll get
(1/x) *sin(x)* cos(x^2) right?
that will still let me with out knowing it, because (1/x) has the limit of 0, and the other ones have no limit altough they are limited.

Answer 3

do you know that the standard limit,
\(\Large \lim \limits_{x\rightarrow0} \dfrac{\sin x}{x}=1\)

Answer 4

and you can just plug in x=0 in cos (x^2)

Answer 5

Ah yah, I forgot that I would also have to change the limit from infinit to 0. and i forgot the limit. Thank you very much

Answer 6

welcome ^_^