(15C) Parallel Resistance, two resistors

[Thomas Klemm]

It's interesting that it was declared as the minimal solution when the obvious solution is shorter:

R1
ENTER ENTER
R2

---

×
x↔y
LST x
+
÷

On the HP-41C we can bring it down to:

ST* Z
+
/

And even Joe can be happy with the result.