Linear Algebra Flashcards
Define hyper-plane
More than 3 variables
Define shew lines
Lines in a 3 dimensional space that don’t intersect and are not parallel
Define homogenous system
A system of equations that all equations equal 0
All constant matrix solutions are 0 in an augmented matrix
Show a system of linear equations
a11x1 +… + a1nxn = b1
am1x1 + … + amnxn = bm
Define scaler
Multiplying a real number with a variable
What is a solution set
All the set of possible solutions
If a system of equations has at least one solution, what is it called
Consistent
How do you solve with elemental operation
Add or subtract 2 or more equations to remove variables and then back substitution
What are the elementary operations
Interchange order of equations
Multiple an equation by a non-zero number
Replace any equation with itself after adding it to a multiple of another equation
Solve using elementary operations
X + 3y + 6z = 25
2x + 6y + 14z = 58
2y + 5z = 19
X = 1
Y = 2
Z = 3
What is an augmented matrix
A matrix with both a coefficient matrix and a constant matrix separated by a line
How are elementary row operations different from elementary operations
elementary row operations are in the form of a matrix
Define leading entry
First non-zero entry of a row when going left to right
Rules followed to create row-echelon form
All non-zero rows are above any rows of zeros
Leading entry of a row is in a column to the right of the leading entry before it, and they are equal to 1
Difference between row-echelon form and reduced row-echelon form
In reduced row-echelon form, all entries above and below the leading entries are zero
What is a pivot position
Location of a leading entry in a row-echelon form
Define pivot column
Column that contains a pivot position
Create row-echelon and reduced row-echelon form of:
0 -5 -4
1 4 3
5 10 7
1 4 3
0 -5 -4
0 0 0
1 0 -1/5
0 1 4/5
0 0 0
What if all variable matrix entries and the constant matrix of an equation equal 0
Infinite solutions
What if all variable matrix entries of an equation equal 0 but the constant matrix entry isn’t zero
No possible solution
What if there are more variables than equations
Rather unlimited or zero soutions
What are the variables of a matrix not in a pivot column
A parameter
Difference in solving Gaussian elimination and gauss-jordan elimination
Gaussian elimination uses back substitution to solve variables
What is a basic variable
A variable entry that is not a parameter
What is a free variable
A variable entry that is a parameter
What is an equivalent matrix
A matrix that can be created from another matrix using elementary row operations
Why do homogenous systems have a trivial solution
The variables can all be zero
Define basic solution
Columns created using the parameters of a solution set
Find basic solutions
X + 4y + 3z = 0
3x + 12 y + 9z = 0
x1 = [-4] x2 = [-3]
[1 ] [0 ]
[0 ] [1 ]
What is a linear combination
Adding column matrixes together
V = a1X1 + … + anXn