HP 48g Graphing Calculator - Manual (Page 256)

solution as formal (symbolic) variables. If they exist in the current
directory, they are evaluated when the quadratic is solved. (Purge a
variable to make it formal.)
4. Optional: Select the result type you wish. (Huneric will attempt
to compute a numerical solution and generate an error message if it
fails.)
5. Optional: Check the PRINCIPAL field if you only want to see the
principal solution (see below).
6. Press OK to solve the quadratic.
20
Getting General and Principal Solutions
HP 48 analytic functions always return one result—the principal
solution. For example, \/i always returns +2, and AS1N(.5) always
returns 30 degrees or 0.524 radians.
However, when you solve an algebraic for a variable, there may be
more than one solution—and you may want to know what they
are. So the ISOL and QUAD commands normally return a general
solution. A general solution represents the multiple solutions by
including special variables that can take on multiple values:
■ si represents an arbitrary + or — sign (+1 or —1). Additional
arbitrary signs in the result are indicated hy s2, s3, . . . . The
“principal” value for arbitrary signs is +1.
■ nl represents an arbitrary integer—0, ±1, d=2, . . . . Additional
arbitrary integers are represented hy n2, n3, . . . . The “principal”
value for arbitrary integers is 0.
ewinci lilt
1. Press MODES) FLAG .
2. Press ;GH;K: until the desired option is displayed for Flag -1.
Exmiiple: Using ISOL to isolate x in the equation y — sin«^, gives
the following results when general and principal solution
options are chosen (in Radians mode):
Principal Solution: ' K= f AS IN ( Y > '.
General Solution: ' N=s 1 *-f < AS IN < Y ) * < -
1 )""nl+Tr*nl > '
20-16 Calculus and Symbolic Manipulation