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\-
Finding Several Roots
of a
Function
v
The function
f(x)
: xs 5x2
10x
+'
20 has three
roots.
:
r(x)
v
The Solver can
find
each
root
by
entering appropriate
guesses
that
v
bracket the
root. One way to determine appropriate
guesses
is
to eval-
uate the
function
at
different
values
of
r
and
look for
places
where
flr)
v
changes
sign. To evaluate an equation, algebraically rearrange
it
so
\,
that all the terms are on the left, and
set
them equal to a "dummy'
variable.
v
Example:
To
find
the three roots
of
the function:
v
f@:f -sxz-1or+20:o
\/
l.
Press
llEor-Vel,
then
ilX.
v
2.
Set
f(x) equal
to the "dummy"
variable
y by
typing:
v
Y=X^3-5xH^2-lgxN+26
tlNPUTl.
v
3.
Press
I
to verify the
equation and display the menu of
variables.
v
4.
Store
various values
of X
and
calculate
Y:
\-/
\,,
\-,
\-,
t(x)
-5
I
I
5
t
t-/
T
I
9: Additional
Eramples
l7g
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