HP 39g+ Graphing manual Symbolic functions, Isolate, Linear?, Quad

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 11-18.)
		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
QUAD	Solves quadratic expression=0 for variable and returns
	a new expression, where variable=newexpression. The
	result is a general solution that represents both positive

and negative solutions by including the formal variable S1 to represent any sign: + or – .

QUAD(expression, variable)

Example

QUAD((X-1)2-7,X) returns (2+s1*5.29150262213)/2

Using mathematical functions 11-17