Hi All, I saw this approach in Denis Howe’s “Aircraft Loading and Structural Layout”, i think it is very convenient for computerized calculations,

Well, this was a thread I didn't need t click on....I'm like a monkey looking at a math problem! What's bad is that 50 years ago I was a straight A math student....sad.

Same here. The local college has free tuition for 'non-conventional' (AKA old) students. I think I did more homework the first semester than I did combined during my first 12 years in public education. But the upside is that it comes back pretty quickly. I still think a graphing calculator isn't needed, or even really useful for basic calculus. But it was required..........and cost me half a grade point learning how to use a TI-89.