- #1
Gear300
- 1,213
- 9
For a set S, there is an identity element e with respect to operation * such that for an element a in S: a*e = e*a = a.
For a matrix B that is m x n, the identity element for matrix multiplication e = I should satisfy IB = BI = B. But for IB, I is m x m, whereas for BI, I is n x n. Doesn't this mean that the two identity elements are different?
For a matrix B that is m x n, the identity element for matrix multiplication e = I should satisfy IB = BI = B. But for IB, I is m x m, whereas for BI, I is n x n. Doesn't this mean that the two identity elements are different?