As you have observed, the graphs of are different if n is odd and
if n is even.
When n is even, the graph is a closed figure which becomes less rounded and more square-like as n increases.
The domain and range are the same as that of the circle, domain [-1, 1] and range [-1,1].
When n is odd, the graph is not a closed figure. The "top" and "right side" of the graph are similar to that of
the next consecutive even number. However, the graph opens up at the top left in a linear fashion and in the
same manner at the bottom right. In addition,
the domain and range are both .