HP 39gs User Manual

Using mathematical functions 13-17
XPON Exponent of value.
XPON(value)
Example
XPON(123.4) returns 2
Two-variable statistics
These are functions for use with two-variable statistics.
See “Two-variable” on page 10-15.
Symbolic functions
The symbolic functions are used for symbolic
manipulations of expressions. The variables can be
formal or numeric, but the result is usually in symbolic
form (not a number). You will find the symbols for the
symbolic functions = and | (where) in the CHARS menu
(
CHARS) as well as the MATH menu.
= ( equals ) Sets an equality for an equation. This is not a logical
operator and does not store values. (See “Test functions”
on page 13-18.)
expression1=expression2
ISOLATE Isolates the first occurrence of variable in expression=0
and returns a new expression, where
variable=newexpression. The result is a general solution
that represents multiple solutions by including the (formal)
variables S1 to represent any sign and n1 to represent
any integer.
ISOLATE(expression, variable)
Examples
ISOLATE(2*X+8,X) returns -4
ISOLATE(A+B*X/C,X) returns -(A*C/B)
LINEAR? Tests whether expression is linear for the specified
variable. Returns 0 (false) or 1 (true).
LINEAR?(expression, variable)
Example
LINEAR?((X^2-1)/(X+1),X) returns 0
HP 39gs English.book Page 17 Wednesday, December 7, 2005 11:24 PM

HP 39gs Specifications

General

Type	Scientific
Form factor	Pocket
Product color	Gray
Internal memory	0.256 MB

Weight and Dimensions

Weight	249 g
Dimensions (WxDxH)	187 x 94 x 31 mm