1What are the 3 ERO's?
ERO 1: $r_i \leftrightarrow r_j$ (swapping rows)
ERO 2: $r_i \to \lambda r_i$ (multiplying by a non-zero scalar)
ERO 3: $r_i \to r_i + \lambda r_j$ (adding rows together)
2What is the result of applying EROs to A? How do you write the resulting matrix in relation to A?
A' where A~A' (~ denotes row equivelancy)
3Does the REF method produce a unique or non unique result?
Non unique result
4Does the RREF method produce a unique or non unique result?
Unique result
5What is the REF method?
1. Choose the row with the furthest left pivot, make this row 1
2. Add or subtract multiples of this row to the other rows in order to make every value below the pivot = 0
3. Ignoring row 1, choose the row with the furthest left pivot, make this row 2
4. Repeat from step 2 with nuance until matrix is in REF
6What is RREF method?
1. Get matrix into REF
2. Multiply the lowest (non-zero) row by $\frac{1}{\text{pivot}}$
3. Add or subtract multiples of this row to the above rows in order to make every value above the pivot = 0
4. Move up a row and repeat from step 2 with nuance until matrix is in RREF
7How do you write the RREF of A?
RREF(A)
8If A is square what can we say about RREF(A)?
either = I or has a row of 0's