Determine all the accumulation point.

[furi0n]

I've faced with some problem in Math. Analysis books of Tom Apostol,
For example, (-1)ⁿ+ 1/m, n,m=1,2,3,4,5...

i think there is no accumulation point but how should i prove this?

thanks for your helps...

 

[mathman]

Since the 1/m term -> 0, -1 and 1 are accumulation points.