Reference Guide

Full Command and Function Reference 3-5
ABCUV
Type: Command
Description: Returns a solution in polynomials u and v of au+bv =c where a and b are polynomials in the
current CAS independent variable, and c is a value.
Access: Arithmetic, !Þ POLYNOMIAL
Input: Level 3/Argument 1: The polynomial corresponding to a.
Level 2/Argument 2: The polynomial corresponding to b.
Level 1/Argument 3: The value corresponding to c.
Output: Level 2/Item 1: The solution corresponding to u.
Level 1/Item 2: The solution corresponding to v.
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: Find a solution in polynomials u and v for the following equation:
x
2
x 1+ +( )u x
2
4+( ) V + 13=
Command: ABCUV(X^2+X+1,X^2+4,13)
Result: {-(X+3),X+4}
See also: IABCUV, EGCD
ABS
Type: Function
Description: Absolute Value Function: Returns the absolute value of its argument.
ABS has a derivative (SIGN) but not an inverse.
In the case of an array, ABS returns the Frobenius (Euclidean) norm of the array, defined as the
square root of the sum of the squares of the absolute values of all n elements. That is:
z
i
2
i 1=
n
∑
Access: !Ê ( Ê is the left-shift of the /key).
Flags: Numerical Results (–3)
Input/Output:
Level 1/Argument 1 Level 1/Item 1
x
→
|x|
(x,y)
→
x
2
y
2
+
x_unit
→
|x|_unit
[array]
→
||array||
'symb'
→
'ABS(symb)'
See also: NEG, SIGN
ACK
Type: Command
Description: Acknowledge Alarm Command: Acknowledges the oldest past-due alarm.
ACK clears the alert annunciator if there are both no other past-due alarms and no other active
alert sources (such as a low battery condition).