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If
the Solver cannot
isolate
the unknown,
it
uses
an
iteratiae (repeti-
tive)
Process
to
search
for a
solution that
sets
the
left
side
of
the
equation equal to the right side. The Solver starts
with
two
initial
esti-
mates
of the answer-your
guesses,
or
numbers
it
generates. Using
one
of
the
estimates,
the Solver
evaluates
the
left
and
right
sides
of
the
equation (LEFT and
RIGHD and
calculates
LEFT
minus
R/GHT
(LEFT
-NGHT).
Then, the Solver repeats the calculation for the other
estimate.
If
neither estimate produces a value
of
0
for
LEFT-KIGHT,
the Solver produces two new estimates that appear to be closer to the
answer.
By repeating this
process
many times, the Solver
approaches
the
answer.
During the iterative
search,
the HP-27S displays the two current esti-
mates and
the sign
of
LEFT-R/GHT
for
each estimate.*
Gurrent estimates
Halting and Restarting an
lterative
Search
The iterative search can take several minutes. You can halt the
search
by
pressing
any
k"y
except
!.
Then,
press
[]
ot
[T'LR
I
to
see
the
best
estimate
the Solver has found.
To
restart the
search
from where
it
left
off,
press
the menu
k"y for
the unknown.
If
the
estimates
don't
seem
to
be proceeding towards a number you
judge to be a reasonable answe[, you can halt the search, enter your
own
guesses,
and restart the
search.
*
A
question mark
beside
an
estimate
indicates
that LEFT-RIGHT
cannot be
calculated
for
that
estimate.
18.
E9SE74
14e7
18. EggE74 14e6
I ],IE:
I I'lE:
T
r
v
Sign
of
LEFT-RIGHT
for
each
estimate
5: The Equation
SolYer
I I
I
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