CASTI-89 TITANIUM · CALC89
identity(
Returns the identity matrix of size n by n.
Syntax
identity(n)
- Group
- Matrix
- Arguments
- Takes the size n.
- Availability
- Included
- Menu path
- MATH ▸ Matrix ▸ CAS ▸ identity(
Example
| Input | Result |
|---|---|
| identity(3) | [[1,0,0][0,1,0][0,0,1]] |
Typing identity(3) on the home screen and pressing ENTER returns [[1,0,0][0,1,0][0,0,1]].
Keystrokes on the TI-89 Titanium
2NDMATH4▶×38
The same key sequence inserts identity( in Calc89, and the AI tutor shows it step by step on the on-screen keypad.
Related commands
- inverse(Returns the inverse of a square matrix, the same result as raising it to the power −1.
- list▶mat(Converts a list into a matrix, filling it row by row with the given number of columns.
- LUComputes the LU decomposition of a matrix with partial pivoting and stores the lower, upper and permutation matrices in variables.
- mat▶list(Returns the entries of a matrix as one list, row by row.
- mRow(Multiplies one row of a matrix by a value, one of the elementary row operations of Gaussian elimination.
- mRowAdd(Multiplies one row of a matrix by a value and adds the result to another row, the key step of Gaussian elimination.
- newMat(Returns a matrix of zeros with the given number of rows and columns.
- norm(Returns the Frobenius norm of a matrix; for a vector this is its length.