1. Implement Problem 9.9 with a MATLAB function crossprod. After implementation, create vectors  and  and compute  and 2. This problem deals with both upper- and lower-triangular matrix...

1. Implement Problem 9.9 with a MATLAB function crossprod. After implementation, create vectors
 and
 and compute
 and

2. This problem deals with both upper- and lower-triangular matrix multiplication.

 Write the algorithm in Problem 9.7 as a MATLAB function, updtrimul and test it with random matrices of size
 and
 For your test, compute
updtrimul
₂
The following statements generate a random, integer, upper-triangular matrix whose entries are in the range
_ij

 Implement the function lowtrimul from Problem 9.13 and test it as in part (a).