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Flashcards in Final Exam Deck (14)
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1

How do you calculate a vector answer

Horizontal Times Vertical (add each digits products together)

2

What is the formula for determining the size of the new matrix

Rows in #1 = Columns in #2

3

How do you determine if multiplying a matrix is possible?

Columns in #1 = Rows in #2

4

How do you multiply a 2x2 or 3x2 or 3x3 Matrix

Take the horizontal row in #1 and multiply by vertical column in #2 .... until all numbers are populated

5

What is the formula for the Inverse

1
___ X adj (A)
det(A)

6

What is the formula for the determinant of a 2x2

ad-bc

7

What is the formula for a determinant of a 3x3

Build 3 row, 5 column table by repeating the first 2 columns

8

How do you know if a determinant isn't possible?

ad-bc = 0

9

How do you build A using Cramers rule in a 2 exponent equation?

ex: 4x + 3y = -23
3x - 5y = 19

[ 4 3]
[ 3 5]

A = x (eq1) , y (eq 1)
x (eq2) , y (eq1)

10

How do you build A-1 using Cramers rule in a 2 exponent equation?

ex: 4x + 3y = -23
3x - 5y = 19

[-23 3]
[ 19 -5]

A-1 = Prod. eq 1, Y (eq 1)
Prod. eq 2, Y (eq 2)

11

How do you build A2 using Cramers rule in a 2 exponent equation?

ex: 4x + 3y = -23
3x - 5y = 19

[4 -23]
[3 19]
A2 = X from both eq, product from both eq.

12

How do you finish using Cramers rule once the tables have been populated?

Find the determinants, then,
Find the X and Y values by dividing the determinants

13

How do you find an X value using a determinate with cramers rule?

X = Det A-1
Det A

14

How do you find a Y value using a determinant with cramers rule

Y = Det 2
Det A