Jack said:
@attbi_s53:
OK, Robert, you got me. Twice I've entered thru SHIFT SOLVE and the first
prompt is "B?"; and I'm not given a chance to enter A. Does this really
work?
Tried a simpler equation, A-squared = B X C-squared, with A=8, C=2. Same
thing happened.
Jack
Solve uses an iterative solver to try to figure out a numerical
solution. Say you want to figure out the right resistor value to make
divider, but you were too lazy to do the algebra in your head. If your
input voltage was 10 volts, and you wanted 1.7 volts out, you could type
1.7 alpha = 10 * alpha A / ( alpha A + alpha B) shift solve
You then get a prompt for A, as in "A? ". Say you want to solve for A.
Then, hit the down key (the bottom of the circular key). You get a "B?"
prompt. Enter a value for B. (say you have a 10k resistor)
10000 =
then get back to the A? prompt by typing up arrow (the top of the
circular key) and type
shift solve
it'll crank for a bit, then display A= on the first line, and 2.048...k
on the second line. Thus, for a value of B=10k, a value of A=2.05k will
get you 1.7V.
The trick is to use the up and down key to enter values for variables
you have values for, and then use shift solve on the one you want the
value for.
--
Regards,
Robert Monsen
"Your Highness, I have no need of this hypothesis."
- Pierre Laplace (1749-1827), to Napoleon,
on why his works on celestial mechanics make no mention of God.