Matrices Flashcards
How do you add and subtract matrices?
Add / subtract each number in the same position of the matrix
How do you know if 2 matrices will multiply?
Number of columns of the first = number of rows in the second one
ie 3x4 x 4x2
Singular
Determinant = 0
Non-singular
Determinant ≠ 0
(AB)^-1
B^-1 A^-1
What order is the transformation AB done?
B followed by A
What does the determinant of a matrix transformation represent?
The area scale factor
What do we say about shears?
x or y axis invariant
Where (1,1) goes to (a,b)
When are equations inconsistent?
When there are no solutions (lines are parallel)
How do you know if the equations are inconsistent?
Try to solve, you’ll get 0y+0z=a
When are equations consistent?
When there are infinitely many solutions (same line)
How do you know if the equations are consistent?
Try to solve, you’ll get 0y+0z=0
