HP -22S Owner's Manual page 164

((x)
((x)
--1---?-->r----'l~
x
--1--------'l~X
4a 4b
((x)
--+--1--+----1.
x
4c
Figure 8-4. Conditions Where
I
SOLVE
I
Can't Find a Root
In addition to the NO ROOT FND error,
I
SOLVE
I
may return a math
error if an estimate produces an unallowed operation-for example,
division by 0, square root of a negative number, or logarithm of O.
You should keep in mind that
I
SOLVE
I
can generate estimates over a
wide range. You can sometimes avoid math errors by using very good
guesses. If
I
SOLVE
I
returns a math error, press
I
RCL
I
unknown variable
to
see the value that produced the error.
Example: A Relative Minimum. Calculate the root of the equation:
x
2 -
6x
+
13
=
0
164 B: More About Solving Equations