I’m assuming your functions are supposed to look like this:

f(x) = \left[ Radius \cdot cos(x \cdot 360), Radius \cdot sin(x \cdot 360), 0 \right];

g(x) = \left[ Radius \cdot cos(x \cdot 360), 0, Radius \cdot sin(x \cdot 360) \right] + \left[ Radius, 0, 0 \right];

The square brackets probably indicate coordinates, which tend to be written using parenthesis in Rhino and Grasshopper. Also the 360 implies this is done in degrees, which will not work in GH. The trigonometric functions all use radians, so 360 becomes 2\pi.

The g function has a vector addition, which seems simple enough to combine into a single statement. Let’s also rename Radius to just r to clean things up. This leaves us with:

f(x) = \left( \hspace{7.5mm} r \cdot cos(2\pi \cdot x), r \cdot sin(2\pi \cdot x), 0 \right)

g(x) = \left( r + r \cdot cos(2\pi \cdot x), 0, r \cdot sin(2\pi \cdot x) \right)

These are just two circle functions. The f function yields in a horizontal circle centred on (0,0,0) with radius r, while the g function yields a vertical circle centred on (r,0,0). Basically, they are just the boundary edges of your shape. You don’t need equations for this, it’s much simpler just generating these circles using circle components.