Machine-translated by Google. Questions are authored in English.
Top

Discussion

The rank of the matrix \(\begin{bmatrix} 1 & 1 & 1 \\ 1 & -1 & -1 \\ 3 & 1 & 1 \end{bmatrix}\) is

  • A.2
  • B.3
  • C.1
  • D.Not possible to determine.

Answer: A

The rank is 2. The third row is twice the first row plus the second row, so the rows are linearly dependent, while the first two rows are not multiples of each other.

\[ 2(1, 1, 1) + (1, -1, -1) = (3, 1, 1) \]

Hence only two independent rows remain and the rank is not 3. It is also not 1, since the first two rows are independent, and the rank can be determined, so the other options are wrong.

No comment is present. Be the first to comment.
Loading…

Post your comment

Please log in or register to post a comment.