What is the variable in the Plateau curve

[dimension10]

When m=2n,

$$x=a(1+2\cos(2nt))$$
$$y=2a\sin(2nt)$$

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.

 

[micromass]

The variable is most likely t. And it gives a circle with center (a,0) and radius 2a.

 

[dimension10]

The variable is most likely t. And it gives a circle with center (a,0) and radius 2a.

Oh, thanks.