Matrices Flashcards
How to add/subtract matrices
Add and subtract the corresponding numbers
The result must be the same
How to multiply matrices
Multiply the outside number by every number inside the matrices
How to solve a matrix equation
Make the corresponding elements equal
If there are extra things, simplify the left side of the equation and solve
How to describe Matrix products
The rows x columns
What is a row
The thing that goes left to right
What is a column
The thing that goes up and down
What are the end dimensions of two matrices being multiplied
Row x column row x column
Result: column x row
To be the same, the outside must be the same
How to multiply two 2x2 matrices
- Multiply the numbers in the first row (up and down) by the numbers in the first column (left and right) add them together.
- Multiply the numbers in the first row of the first matrix by the numbers in the second column of the second matrix and add them.
- Multiply the numbers in the second row of the first matrix by the numbers in the first column of the second matrix and add theme.
- Multiply the numbers in the second row of the first matrix by the numbers in the second column of the second matrix and add.
- Simplify
How to find the determinant of a 2x2 matrix
Multiply left to right diagonal (top first)
Subtract
How to find the determinant of a 3x3 matrix
Repeat the first two lines on the outside of the matrix
Multiply left to right (top first)
Add the numbers up and subtract the two wholes
Area of a triangle
(Must always be…)
+/- 1/2
[x1. Y1. 1]
[x2. y2. 1]
[x3. y3. 1]
Must always be positive
How to find the determinant with two equations
D= a,b
Dx= d,b
Dy= a,d
X=Dx/D
Y=Dy/D
How to find the determinant with 3 equations
D= a,b,c
Dx= d,b,c
Dy= a,d,c
Dz=a,b,d
X=Dx/D
Y=Dy/D
Z=Dz/D
