It took me some month to search the Internet for standard „Algebraic Surfaces“ and translate them for a Blender geometry node use. Sure there are some more objects, but now I can offer you three packages with about 75 complex mathematical equations.  

Here are 3 sets, each containing 25 Algebraic Surface made for blender use. Similar to the XYZ Function Add-on but "non-destructive". That means you can change with the parameters in the geometry modifier the View, the Form, the Size and you are able to go back to your start whenever you want, without beginning new.

Please notice, even if the structure is rather simple, you should have worked before with Geometry Nodes. If you never worked before with Geometry Nodes it might be the chance to get a bit deeper in this field. Be aware, even if i tried to make it as simple as possible, you have to know a bit about the function of Geometry nodes in Blender. On Blend Exchange you will find a "free Version" with only three objects to see how it works. So please try the free Version before you decide to buy those Sets - to see if it suits for your needs. Free File Link

PS: you will find 80 3D objects in a small showcase on my Website 

UPDATED VERSION 2024

• All Objects are usable as assets
  
• A Flip Face Button is integrated for a easy change
• Material Slots are placed in the GN Modifier
• Multiple performance clean up
• There is the the simple "Add Mesh" version if you don’t want to use geometry nodes.