retagged by
911 views
4 votes
4 votes
Let $A$ be a matrix defined as $A=u v^T$, where $u$ and $v$ are column vectors of dimension $3 \times 1$. The resulting matrix $A$ will be of dimension $3 \times 3$. What are the maximum number of nonzero eigenvalues possible for the matrix $A?$
retagged by

1 Answer

0 votes
0 votes

A = uu*

where u is a 3x1 matrix
so, u* is a 1x3 matrix

The key to this question is AB and BA share non-zero eigenvalues

Lets say, B = u*u
So, B will be a 1x1 matrix

Hence, B will have only 1 eigenvalue

Therefore, Out of 3 eigenvalues of A, only 1 (sharable by B) will be non-zero. Other 2 eigenvalues will be 0.

Answer is 1

Answer:

Related questions

608
views
1 answers
5 votes
GO Classes asked Jan 13
608 views
Consider the system $A \mathbf{x}=\mathbf{b}$, with coefficient matrix $A$ and augmented matrix $[A \mid b]$. The sizes of $\mathbf{b}, A$ ... exists) if and only if $\operatorname{rank}[A]>$ $\operatorname{rank}[A \mid b]$.
559
views
1 answers
3 votes
GO Classes asked Jan 13
559 views
The figure above shows an undirected graph with six vertices. Enough edges are to be deleted from the graph in order to leave a spanning tree, which is a ... having the same six vertices and no cycles. How many edges must be deleted?
695
views
1 answers
7 votes
GO Classes asked Jan 13
695 views
An MIPS pipeline has five stages, with a clock cycle of $200 \mathrm{ps}$. Suppose that this MIPS pipeline is redesigned to have four stages, with a ... , what speedup will this new design achieve when compared to the five-stage pipeline?
716
views
1 answers
4 votes
GO Classes asked Jan 13
716 views
Consider the bit pattern $10110110.$ Interpret this bit pattern as a $8$-bit $2$'s complement number. What is the largest magnitude negative number that can ... overflow? (Write your answer in decimal, only the magnitude, not the sign)