A proxy for this value, called its “stable” variant, equals the square of the Frobenius norm divided by the square of the spectral norm. The reduction of this quantity is most efficiently performed by truncating a singular value decomposition according to the Eckart-Young theorem. If an object has a value of k for this quantity, then its minimal polynomial may have degree up to k plus 1. The (*) outer product of two nonzero vectors u and v always has a value of 1 (-5[1])for this quantity. This quantity and the nullity sum (10[1])to the number of columns in a matrix. (10[1])An n-by-n matrix has a value of n for this quantity (10[2])if and only if it is invertible. The “row” and “column” varieties of this quantity are equal for any matrix. For 10 points, name this quantity which is the dimension of a matrix’s column space. ■END■