Follow-up to my 1/18/22 post, "Generating a hemispherical dome surface plot using a cosine function"

On Jan. 21, 2022, Werner_E provided the solution for creating color-coded mesh surface plots using Mathcad Prime 6.0 for two functions [f1(x) and f2(x)] I had defined [Solved: Re: Generating a hemispherical dome surface plot u... - PTC Community]. Assuming that these instructions could be utilized to create similar plots with any other monotonic function, I defined and inserted two new functions [f3(x) and f4(x)- -see below] in the equation S = CreateSlices(f1, 0, a, 5):

f3 = e–cx/a        f4 = 1 – x/a, both over 0 ≤ x ≤ a, with a = 300, c = 4.61

Evidently my simplistic assumption was incorrect- -the Insert 3D Plot command failed to generate the anticipated five-color slice hemispherical domes whose height ranges between 0 and 1.0. Where did I go wrong?