HP 50g Graphing, 48gII Graphing manual Lname, Lncollect, LNP1

Input/Output:

		Level 1/Argument 1		Level 1/Item 1
		z	→	ln z
		'symb'	→	'LN(symb)'
See also:	ALOG, EXP, ISOL, LNP1, LOG
LNAME
Type:	Command
Description:	Returns the variable names contained in a symbolic expression.
Access:	Catalog, …µ
Input:	A symbolic expression.
Output:	Level 2/Argument 1: The original expression.
	Level 1/Argument 2: A vector containing the variable names. The variable names are sorted by
	length, longest first, and ones of equal length are sorted alphabetically.
Flags:	Exact mode must be set (flag –105 clear).
	Numeric mode must not be set (flag –3 clear).
Example:	List the variables in the expression COS(B)/2*A + MYFUNC(PQ) + 1/T.
Command:	LNAME(COS(B)/2*A + MYFUNC(PQ) + INV(T))
Result:	{COS(B)/2*A + MYFUNC(PQ) + 1/T, [MYFUNC,PQ,A,B,T]}
See also:	LVAR
LNCOLLECT
Type:	Command
Description:	Simplifies an expression by collecting logarithmic terms. For symbolic powers does not perform
	the same simplification as EXP2POW; compare example 2 here with example 2 for EXP2POW.
Access:	Algebra, …×, !Ð, or PLEXP & LN, or !Ú REWRITE L
Input:	An expression.
Output:	The simplified expression.
Flags:	Exact mode must be set (flag –105 clear).
	Numeric mode must not be set (flag –3 clear).
	Radians mode must be set (flag –17 set).
Example 1:	Simplify the following expression:
	2(ln(x)+ln(y))
Command:	LNCOLLECT(2(LN(X)+LN(Y))
Result:	LN(X^2*Y)
Example 2:	Compare the effect of LNCOLLECT with the effect of EXP2POW on the expression e nln( x)
Command:	LNCOLLECT(EXP(N*LN(X))
Result:	EXP(N*LN(X))
See also:	EXP2POW, TEXPAND
LNP1	Analytic function
Type:
Description:	Natural Log of x Plus 1 Analytic Function: Returns ln(x + 1).
	For values of x close to zero, LNP1(x) returns a more accurate result than does LN(x+1). Using
	LNP1 allows both the argument and the result to be near zero, and it avoids an intermediate
	result near 1. The calculator can express numbers within 10449 of zero, but within only 10–11of 1.
	For values of x < –1, an Undefined Result error results. For x=–1, an Infinite Result exception
	occurs, or, if flag –22 is set, LNP1 returns –MAXR.
Access:	!´HYPERBOLIC LNP1		( ´is the leftshift of the	Pkey).

3136 Full Command and Function Reference