So far the way I have determined accumulation points of given sequences or relations has been by drawing them out. However I would like some clarification to see if my thinking is correct or not.
a) $z_n=i^n$, n being a natural number. What I got by graphing is that depending on the n value the only numbers are 1,-1, i, or -i. Would these be the accumulation points then?
b) $|z|>1, 0\leq arg(z)<\frac{\pi}{4}$. I think this is basically the region outside the circle with radius one and bounded by a 45 degree border. so would the accumulation point be positive infinity?