HP HP-28S User Manual

9
Symbolic Solutions
This chapter describes two methods for finding symbolic solutions.
There is a simple method for solving a quadratic expression by cal-
culating the linear expression that represents both zeros. There is also
a
more versatile method that provides a symbolic solution for a vari-
able in more general equations.
Each
method works with both expressions and equations. The zero of
an expression f(x) is the same as the root of the equation f(x) = 0, and
the root of the equation f(x) = g(x) is the same as the zero of the
expression f(x) - g(x).
Finding the Zeros of a Quadratic Expression
You can find both zeros of a quadratic expression without plotting or
making estimates. The following example solves x
2
-
6x + 8.
Before starting the example, clear the stack and select STD number
display mode .
• 1 CLEAR I 1
3
:
I
.1 MODE I STD~IIiBII_maDBI:mm:::I
Put the expression on the stack.
~ X .~ 2 B 6 0 X G 8 I ENTER I
9: Symbolic Solutions 107

HP HP-28S Specifications

General

Brand	HP
Model	HP-28S
Category	Calculator
Language	English