Augmented Matrices I Matrix an arrangement of s

Augmented Matrices I. . Matrix = an arrangement of #s in rows and columns. A) Matrix: (plural is matrices). Symbol [ ] B) Order / Size of a matrix = (rows x columns) 1) number of rows by # of columns C) Entries = the numbers inside of a matrix. D) Matrices are named with a capital letter. E) Square matrix: # of rows = # of columns. 1) (2 x 2), (3 x 3), etc.

Augmented Matrices II. . Augment = to enhance, to make something bigger. A) Augmented matrix = a linear system written as a single matrix. 1) ax + by = # a b # cx + dy = # Example: 3 x + 4 y = – 6 2 x – y = 7 c d 3 2 # or 4 – 1 – 6 7 c d #

Augmented Matrices III. . Solving Augmented Matrices with the N-spire A) B) C) D) E) Use black math icon Menu 7 , 5 [Reduced Row-Echelon Form] Menu 7 , 1 [Create] Choose the size of your augmented matrix. Type in the numbers (use the “tab” button to jump to the next box) F) Press ENTER to get your answer. Example: 3 x + 4 y = – 6 3 4 – 6 1 0 2 2 x – y = 7 2 – 1 7 0 1 – 3 The solution is (2 , – 3)

Augmented Matrices on TI-84 I. . Entering a Matrix into the calculator. 1) Press MATRIX 2) Go to EDIT (2 nd Matrix) (use scroll arrows) 3) Chose the desired matrix letter & press ENTER. 4) Use the scroll arrows to move the cursor. Enter in the order / size of the matrix. 5) Type in the entries. Press enter after each one. 6) Press 2 nd QUIT to exit the matrix screen.

Augmented Matrices on TI-84 III. . Using rref to Solve Systems of Equations. A) Put the system into augmented matrix form. 1) Enter in the augmented matrix. (2 x 3) or (3 x 4) 2) Press 2 nd QUIT to exit the matrix screen. 3) Press MATRIX (2 nd Matrix) 4) Go to Math and go down to “rref”. ENTER. 5) Press MATRIX & chose desired matrix. 6) Press ENTER to perform the math.