Counting operations for a matrix power

edited January 22 in Problems

This is a bit of a variation on problem 1.7.2 from our text.

Let $A \in \mathbb R^{n\times n}$. How many multiplications are required to compute $A^8$?


  • dandan
    edited January 27

    Since A is a square matrix we can use the formula:
    $$\frac{(n^3)-n}{3}, n = 8$$
    Which comes to 168

    Edit: is this problem asking how many multiplications are needed to compute an n x n matrix by itself 8 times?

  • @dan Hmm... $n$ refers to the dimension of the matrix, not the matrix power. It's not 8; rather; it's unspecified so that your final answer should depend upon $n$.

Sign In or Register to comment.