This handful of MATH is precisely what I was referring to as the prerequisites: notation, numbers, sets, equations (and the general procedure for solving them), functions, and a bit of geometry. I agree that with these concepts in place, you can tackle A LOT of topics, possibly filling in other knowledge in a just-in-time manner. This is what I find very fascinating (and a big part of my startup's mission): the fact that (re)learning a handful of math topics opens so many doors, that currently a vast number of adults are keeping firmly shut because they believe they are not "math people."
* Sorry for the confusion: there is a typo in my comment, I meant to write my book is on MECH+CALC, and the prerequisite are the handful of MATH topics you listed.
Have you heard about stokes theorem? Or Fourier Transforms? Those aren't particularly high level math concepts, but they have years worth of math prerequisites, without prerequisites there is no way to understand such things properly, and there are things that are way deeper with more prerequisites than those.
And those aren't some arbitrary equations, they are core concepts that are very useful in so many situations. There is a reason those are taught to most engineers.