Domes and cones

I’m brand new to Grasshopper and am trying to create a rule so that the diameter of the circle at the base of the cone has an inverse relationship to the vertex, and the shorter the distance to the vertex, the ‘pitch’ of the cone in decreases.

I have attached an illustration of what i need to accomplish.

I’ve tried using a separate curve, and then using revolution to make the cone/dome/convex cone (I dont think thats the correct term), and use a simple quadratic expression: y=mx^2, where m=k/(dist from base midpoint to vertex.

I’ve been reading the manuals, and I think a superior method for this rule is to use the nurbs curve panel

How the central point pass from tangent to sharp? What is the logic there?

In the meantime see this: (9.2 KB)

I think I understand your question:

What I have described isnt possible essentially, although I think the dome for me will suffice, what you have given is helpful, Im experimenting with it now.

Sorry I wasnt thinking about it hard enough when describing my problem, as I said this stuff is new to me.