Grasshopper, sine(cos) surface

[aijapanese]

hi, I want to create this sin or cos surface.
I tried but I cannot.

I want to learn how to do.
So, I want to ask anyone who can answer.

[maje90 (Riccardo Majewski)]

waves.gh (7.6 KB)

[aijapanese]

Thak you so much!
I will try it!