HP 48GII

Computer Algebra Commands 4-77
TRUNC
Type: Function
Description: Truncates a series expansion.
Access: Catalog, …µ
Input: Level 2/Argument 1: The expression that you want to truncate.
Level 1/Argument 2: The expression to truncate with respect to.
Output: The expression from Level 2/Argument 1, with terms of order greater than or equal to the
order of the expression in Level 1/Argument 2 removed.
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: Expand the expression (x+1)
7
, and remove all terms in x
4
and higher powers of x
Command:
TRUNC((X+1)^7,X^4)
Result: 35*X^3+21*X^2+7*X+1
See also: DIVPC, EXPAND, SERIES
TSIMP
Type: Command
Description: Performs simplifications on expressions involving exponentials and logarithms. Converts base
10 logarithms to natural logarithms
Access: Exponential and logarithms, !Ð L, or …ÑLL
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).
Example: Simplify log(x+x)
Command:
TSIMP(LOG(X+X))
Result: (LN(2)+LN(X))/(LN(5)+LN(2))
See also: TEXPAND, TLIN
UNASSIGN
Type: Command
Description: Removes global variables and returns their values. This is an algebraic version of the PURGE
command.
Access: Catalog, …µ
Input: Level 1/Item 1: The name of a global variable, or a list of global names, to be purged.
Output: Level 1/Item 1: The value or list of values that were stored in the now purged variables. If a
variable does not exist, or is not in the current directory path, it is not removed, and its name
is returned.
Flags: The status of the purge confirm flag (flag –76) is ignored, variables are purged with no request
for confirmation.
Example: Try to remove the global variable U, which contains 17.5, and the global variable V, which is
not on the current directory path.