If matrix A has dimension 3 x 4 and matrix B has dimension 4 x 2, what is the dimension of product matrix AB?
Answer and explanation
Correct answer: D. 3 x 2
- Step 1: Matrix multiplication of (m x n) and (n x p) produces a matrix of size m x p. Step 2. Here, (3 x 4) multiplied by (4 x 2) yields dimension 3 x 2. Answer: 3 x 2. Why not the others: 4 x 4 uses inner dimensions; 3 x 3 is square; 2 x 3 reverses rows and columns.
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