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 n·ln(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 10-449of 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 left-shift of the Pkey).

3-136 Full Command and Function Reference