Powmod; Preval; Prevprime - HP 48gII Advanced User's Reference Manual

Description: Rewrites an expression raised to a power as a product. If followed by repeated execution of
DISTRIB allows an expression to be expanded fully, step by step.
!Ú
Access:
Input: An expression raised to a power.
Output: The result from applying the distributive property of exponentiation over multiplication.
Flags: Exact mode must be set (flag –105 clear).
Numeric mode must not be set (flag -3 clear).
Example: Expand
Command:
POWEXPAND((X+1)^3)
Result:
(X+1) (X+1) (X+1)

POWMOD

Type: Function
Description: Raises an object (number or expression) to the specified power, and expresses the result
modulo the current modulus.
Access: Arithmetic,
Input: Level 2/Argument 1: The object.
Level 1/Argument 2: The exponent.
Output: The result of the object raised to the exponent, modulo the current modulus.
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).

PREVAL

Type: Function
Description: With respect to the current default variable, returns the difference between the values of a
function at two specified values of the variable.
PREVAL can be used in conjunction with INTVX to evaluate definite integrals. See the
example below.
Calculus, !Ö
Access:
Input: Level 3/Argument 1: A function.
Level 2/Argument 2: The lower bound.
Level 3/Argument 1: The upper bound.
The bounds can be expressions.
Output: The result of the evaluation.
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: Evaluate the following:
3
3
∫
x + 3x
0
Command:
PREVAL(INTVX(X^3+3*X),0,3)
Result:
135/4

PREVPRIME

Type: Function
4-58 Computer Algebra Commands
L
REWRITE
(X+1) .
3
Þ L
!
MODULO
. &
DERIV INTEG
x d
L.