In TI Nspire, matrix multiplication can be accomplished in the Calculator page. The process is intuitive and easy with the visual templates.
Firstly use the matrix template to define one:
Then simply do multiplication after filling in the matrix elements.
Doing so in Excel required the use of the MMULT() function. A little trick is needed for this function for returning answer in array format – by pressing CTRL+SHIFT+ENTER at the same time after inputting the function for the cells selected as output array.
First step, fill in the matrix with the elements into respective cells.
Mark the output region to use the array function. In this example it is also a 3×3 matrix.
Apply the MMULT() function on the upper left corner cell of the region selected.
The trick is here, when finished typing in the function, press CTRL+SHIFT+ENTER instead of just ENTER. The answer from the function will then be populated in the selected cells, and the formula will be displayed with curly brackets enclosed, like {=MMULT(B2:D4,F2:H4)}.
