13 Sep
2020
13 Sep
'20
9:44 p.m.
Grant Taylor via TUHS <tuhs(a)minnie.tuhs.org> writes:
For example, let's start with Pythagorean
Theorem
a² + b² = c²
[...]
[a] [enter]
[a] [enter]
[multiply]
[b] [enter]
[b] [enter]
[multiply]
[add]
[square root] # to solve for c
I do
[a] [square]
[b] [square]
[plus]
[square root]
6 keys. (Many operations push the entered value into the x register
without needing the enter key. Also, like with infix calculators,
usually there is a [x^2] key -- in postfix notation on both!)
[a]
[square]
[plus]
[b]
[square]
[square root]
That would give you the value of [b] and leave some rest of the
operation in the (hidden) registers. Actually you need
[a] [square]
[plus]
[b] [square]
[=]
[square root]
7 keys.
Although I started with infix calculators, I find it easier to work
my way out of more complex nested formulas with RPN than to track
the level of parentheses in my mind. Consider something like this:
3y * x / (z + 4k)^2 2w + v! \
------ * | ---------- + ---------- |
5b + z \ 3b * 4x ln(x + 2y) /
Now this is a PITA either way, but it comes easier for me with RPN.
[Sorry for the late reply -- I subscribed to TUHS earlier this year
and am only now making my way through it.]
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