Multiply two matrices. Enter both with rows separated by semicolons and values by commas.
Usage Tip
Order matters in matrix multiplication — AB and BA are generally different, and one may not even be defined.
A’s column count must equal B’s row count
It is not commutative: A times B usually differs from B times A.
The result has A’s row count and B’s column count.
Enter rows separated by semicolons, values by commas.
Matrix multiplication combines rows of the first matrix with columns of the second. Each entry in the result is the sum of the products of a row from A and a column from B. For this to work, the number of columns in A must equal the number of rows in B, and the result has the number of rows of A and the number of columns of B.
Unlike ordinary multiplication, matrix multiplication is not commutative, so A times B is usually different from B times A and may not even be defined in both orders. It is associative, so the grouping of three matrices does not change the answer. Multiplying by the identity matrix leaves a matrix unchanged.