- Joined
- May 27, 2016
- Messages
- 3,469
(Sigh).. You are right!I'm going to speculate that the advent of modern technology (computers and the Internet) have made the use of this type of convenience (conductivity proportional to area) much less of a useful thing. Most people are quick to look this type of thing up in an online chart than actually crunch numbers, and if so can do it on a calculator so pi * r^2 isn't tough.
A similar issue, how many people care memorized for small angles:
the tan(x) is approx the same as the sin(x) which is approx x/60? (for an angle x measured in degrees)
Why bother, won't a calculator do that exactly? (@graham-xrf might know why I picked this up)
I guess you got to know me a bit. I don't know quite when I became a precision-minded numeric freak, but folk around me now know that they can't borrow my calculator without getting into a knot over why it does not have an "=" equals button (HP-35S Reverse Polish Scientific)
. The calculator app on my phone is the same.