# The Solver; Finding A Zero Of An Expression - HP -28S Manual

8
The Solver
This chapter describes how to find a zero and a minimum of the ex-
pression you plotted in the previous chapter. Work through the steps
in the previous chapter if you haven't done so already, because you'll
need some of the results from that chapter.
For a complete description of the Solver, refer to "SOLVE" in the Ref-
erence Manual.
Finding a Zero of an Expression
The following example assumes that the expression
x
3 -
x
2 -
X
+
3
is still the current equation and that you've created the variable
PPARl, as described in the previous chapter. You'll plot the expres-
sion again, digitize an estimate for a zero of the expression, and then
use the Solver to find a more accurate value for the zero.
Before starting these examples, clear the stack, select Radians angle
mode, and select FIX 2 number display mode .
1
CLEAR
I I
=3-:
-------------,1
~I ~~~E
:
Purge the existing PPAR to ensure that the next plot uses the default
plotting parameters .
1
PLOT
II
NEXT
I
1
3 :
I
l2J
PPAR
.1
PURGE
I
I:
~lDBli1IIBtrnmll:DlI:mI
98
8: The Solver