HP 33s User Manual
Page 329
More about Solving
D–5
|
/
/
Checksum and length.
Cancels Equation mode.
Now, solve the equation to find its positive and negative roots:
Keys:
Display:
Description:
0
I
X 10
_
Your initial guesses for the
positive root.
| H
%:-%.
Selects Equation mode; displays
the equation.
X
#
%/
)
Calculates the positive root
using guesses 0 and 10.
)
Final two estimates are the
same.
|
)
f(x)
= 0.
0
I
X 10
^
. _
Your initial guesses for the
negative root.
| H
%:-%.
Redisplays the equation.
X
#
%/
.)
Calculates negative root using
guesses 0 and –10.
|
)
f(x)
= 0.
Certain cases require special consideration:
If the function's graph has a discontinuity that crosses the x–axis, then the
SOLVE operation returns a value adjacent to the discontinuity (see figure a,
below). In this case, f(x) may be relatively large.
Values of f(x) may be approaching infinity at the location where the graph
changes sign (see figure b, below). This situation is called a pole. Since the
SOLVE operation determines that there is a sign change between two
neighboring values of x, it returns the possible root. However, the value for f(x)
will be relatively large. If the pole occurs at a value of x that is exactly
represented with 12 digits, then that value would cause the calculation to halt
with an error message.