HP 39gs Graphing manual Two-variable statistics, Symbolic functions, Xpon, Isolate, Linear?

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

Using mathematical functions 13-17