HP HP-28S - Isolating a Variable

Now make sl a negative sign.
-1
Return the second solution to level
1"'1 1
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1.
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The two roots of x
2
-
6x + 8 are x
4 and x 2.
Isolating a Variable
The HP-28S can isolate a single occurrence of a variable in an equa-
tion, returning an expression representing the symbolic solution of
the equation. In other words, if x is the variable for which the equa-
tion is solved, and a, b, and c are the other variables in the equation,
isolating x produces an expression in a, b, and c such that the equa-
tion is satisfied when x has the value of the expression.
For the first example, isolate x in the equation
a(x + 3) - b = c.
This example is simple because there is only one occurrence of x. Later
examples show how to manipulate the equation to produce a single
occurrence of x.
Clear the stack .
• 1 CLEAR 1
Put the equation on the stack.
c:J A 0 CD X G 3 .OJ G B 0 c
1 ENTER 1
3:
2:
1: 'A*(X+3)-B=C'
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9: Symbolic Solutions 109