 Solution

ID: past-exam-of-the-year-1-of-the-computer-science-course-of-the-university-of-oxford/2021/digital-systems-linear-algebra-introduction-to-formal-proof/4/a/ii/solution

D_{ii} = \sum_{k = 1}^{N} B_{ik} C_{ki}

. Only

k = i

can contribute, so $D_{ii} = B_{ii} C_{ii}$ . This also shows that the product is a diagonal matrix, with its diagonal obtained by entrywise multiplication of the two diagonals.

 New to topics? Read the docs here!