Determinant

What is the determinant

• Area IIRC

How to find Determinants

• How to find determinant

  • 3x3

  • Bigger than 3x3

    • in general, let A be a nxn matrix with $n\ge 3$ and let $A(i,j)$ denote the $(n-1)(n-1)$ sub matrix of A with the $ith$ row and $jth$ column removed. th

• Co factor expansion

  • THE CROSS

    • 
    • 
      • this is just showing that we must multiply the original cross man
    • we must make it + - + - for adding the guys and it goes on like that pattern like a checkerboard for the entire matrix

• We can just adjust the starting the det row/column

  • by just changing the start line to the one with the most 0 entries but we must adhere to the checkerboard
    • 

Properties of determinants:

• the determinant of an upper-traigular, lower-triangular, or diagonal matrix is the product of the diagonal entries.

Example

• More than 3x3

  • its just the cross but you get the matrix size down, then you keep doing it until you get a 2x2 matrix :/