[sdiy] Equation question

[David G. Dixon]

> Well, not to be pedantic

Then DON'T BE!!   ;->  (did you notice the winking emoticon?)

But seriously, folks, let's not throw out the baby before the bathwater's
even cold!  There's plenty of time to learn to appreciate the finer points
of opamps, once the basic "golden rules" have been thoroughly assimilated
and internalized.  90% of everything anyone needs to know about opamps is
encapsulated in the golden rules.

Just for fun, I'll repeat them:

1.  the input pins admit no current
2.  the input pins share the same voltage