If you only want to create a function graph you could simply create a model like this one:



Then, in the vertex shader, you take the InPos.x value as the argument of your function (you may have to scale or shift the value, f.i. with vecSkill41, so it fits your argument) and simply apply it to the formula you have. There is no need for VS 3.0 or higher and no need for mesh generation then.