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

Discussion

A 3 by 3 matrix has determinant 5. The determinant of twice that matrix is

  • A.5
  • B.20
  • C.40
  • D.10

Answer: C

Each of the three rows contributes one factor of \( k \), so for a matrix of order \( n \):

\[ \det(kA) = k^{n}\det A \]

\[ \det(2A) = 2^{3}\times 5 = 8 \times 5 = 40 \]

Using a single factor of two and reporting 10 is the classic error with this property.

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

Post your comment

Please log in or register to post a comment.