When m=2n, [tex]x=a(1+2\cos(2nt))[/tex] [tex]y=2a\sin(2nt)[/tex] where a is a constant. The graph is a circle. Now, what is the variable with respect to which the functions x and y are calculated? Is it n or t? When I tried it on Microsoft Excel, neither created a circle. So I really don't know which one is the variable. Thanks.