What is the value of the determinant of the matrix \( A = \begin{pmatrix} 1 &

Practice Questions

Q1
What is the value of the determinant of the matrix \( A = \begin{pmatrix} 1 & 2 & 3 \\ 4 & 5 & 6 \\ 7 & 8 & 9 \end{pmatrix} \)?
  1. 0
  2. 1
  3. 2
  4. 3

Questions & Step-by-Step Solutions

What is the value of the determinant of the matrix \( A = \begin{pmatrix} 1 & 2 & 3 \\ 4 & 5 & 6 \\ 7 & 8 & 9 \end{pmatrix} \)?
  • Step 1: Identify the matrix A, which is given as A = [[1, 2, 3], [4, 5, 6], [7, 8, 9]].
  • Step 2: Understand that the determinant is a special number that can be calculated from a square matrix.
  • Step 3: To find the determinant of a 3x3 matrix, we can use the formula: det(A) = a(ei - fh) - b(di - fg) + c(dh - eg), where the matrix is structured as follows: A = [[a, b, c], [d, e, f], [g, h, i]].
  • Step 4: For our matrix A, we have: a = 1, b = 2, c = 3, d = 4, e = 5, f = 6, g = 7, h = 8, i = 9.
  • Step 5: Substitute these values into the determinant formula: det(A) = 1(5*9 - 6*8) - 2(4*9 - 6*7) + 3(4*8 - 5*7).
  • Step 6: Calculate each part: 5*9 = 45, 6*8 = 48, so 5*9 - 6*8 = 45 - 48 = -3.
  • Step 7: Next, calculate 4*9 = 36, 6*7 = 42, so 4*9 - 6*7 = 36 - 42 = -6.
  • Step 8: Then, calculate 4*8 = 32, 5*7 = 35, so 4*8 - 5*7 = 32 - 35 = -3.
  • Step 9: Now substitute these results back into the determinant formula: det(A) = 1*(-3) - 2*(-6) + 3*(-3).
  • Step 10: Simplify: det(A) = -3 + 12 - 9 = 0.
  • Step 11: Conclude that the determinant of matrix A is 0, which indicates that the rows of the matrix are linearly dependent.
No concepts available.
Soulshift Feedback ×

On a scale of 0–10, how likely are you to recommend The Soulshift Academy?

Not likely Very likely