3-80 Full Command and Function Reference  
i 
Type: Function 
Description: i Function: Returns the symbolic constant i or its numerical representation, (0, 1). 
Access:  !¥
     (¥is the left-shift of the Ikey). 
Flags:  Symbolic Constants (–2), Numerical Results (–3) 
Input/Output: 
 
Level 1/Argument 1    Level 1/Item 1 
 
→ 
'i' 
 
→ 
(0,1) 
See also:  e, MAXR, MINR, π 
 
 
IABCUV 
CAS:  Return a solution in integers u and v of au + bv = c, where a, b, and c are integers. 
 
IBASIS 
CAS:  Determine the basis of the intersection between two vector spaces. 
 
IBERNOULLI 
CAS:  Return the nth Bernoulli number for a given integer n. 
 
IBP 
CAS:  Integration by parts of a product of two functions, given the antiderivative of one function. 
 
ICHINREM 
CAS:   Solve a system of two congruences in integers using the Chinese Remainder theorem. 
 
IDN 
Type: Command 
Description: Identity Matrix Command: Returns an identity matrix; that is, a square matrix with its diagonal 
elements equal to 1 and its off-diagonal elements equal to 0. 
  The result is either a new square matrix, or an existing square matrix with its elements replaced 
by the elements of the identity matrix, according to the argument. 
•  Creating a new matrix: If the argument is a real number n, a new real identity matrix is 
returned, with its number of rows and number of columns equal to n. 
•  Replacing the elements of an existing matrix: If the argument is a square matrix, an identity 
matrix of the same dimensions is returned. If the original matrix is complex, the resulting 
identity matrix will also be complex, with diagonal values (1,0). 
•  If the argument is a name, the name must identify a variable containing a square matrix. In 
this case, the elements of the matrix are replaced by those of the identity matrix (complex if 
the original matrix is complex). 
Access:  !Ø  
CREATE IDN   ( Ø  is the left-shift of the 5key). 
  !´
MATRIX MAKE IDN  ( ´ is the left-shift of the Pkey). 
Input/Output: 
 
Level 1/Argument 1    Level 1/Item 1 
n 
→ 
[[ R-matrix
identity
 ]] 
[[ matrix ]] 
→ 
[[ matrix
identity
 ]] 
'name' 
→ 
[[ matrix
identity
 ]]