1.1 Systems of Lin Eqns Flashcards
1
Q
Matrix
A
a rectangular array (block) of numbers
2
Q
3 Rules of Row Operations
A
( 1 ) switch two rows
( 2 ) multiply a row by a non-zero #
( 3 ) add a multiple of a one row to another row
3
Q
Pivotal variables are…..
A
basic
4
Q
Non-pivotal variables are….
A
free
5
Q
When is a system consistent?
A
at least one solution
6
Q
Free variables
A
= infinitely many
7
Q
One solution
A
a unique solution
8
Q
Infinitely many solutions if
A
( 1 ) the sys is consistent
2 ) the sys has more variables then equations (n > m
9
Q
Three important questions
A
( 1 ) is the linear system consistent?
( 2 ) is the solution unique?
( 3 ) are the solutions efficient?
