#Reduce Row Echelon Matrix
slender epochBOT
slow swan
I have another question about reduced row echelon matrixs
I did this problem and I think I did all the step’s correctly, but I seem to be seeing different answers online. Am I in the wrong? If so in which part? Thanks!
lapis drift
@slow swan In your first step you did not do R1 = -R2 + R1 correctly
take a look at the position (1,3)
row 1 column 3
slow swan
Oh dang it would be -1
slow swan
row 1 column 3
Well now that messes up the whole problem. So would I have to take a different approach?
lapis drift
no your approach is correct, it just needs to be tweaked a little
also, are you going for REF or RREF
lapis drift
on what part
lapis drift
i would recommend doing R3-R1 first to clear the spaces under your pivot position (R1 C1)
then you would do R1 = R1 - R2
slow swan
then you would do R1 = R1 - R2
Is this to change row 1?
lapis drift
yea sorry
lapis drift
R1 = R1 - R2 would not change the second zero
its very similar to what you just did
this is what your matrix would look like after those two operations @slow swan
then you would continue simplifying to RREF
slow swan
Ok ok I think I got it
I was looking at my old work that was wrong
Ok so can we add row 2 and 3 to turn -1 to 0 on R3
lapis drift
yes exactly
lapis drift
yes
slow swan
Then finally add row 1 and 2 to get R1
lapis drift
not quite
if you do R1 = R1 + R2 youll have a 1 in row 1 column 2, which you do not want
lapis drift
yes thats right
slow swan
Awesome
lapis drift
then you still have one more step
slow swan
Turn it into a equation then solve for each variable?
lapis drift
well you can do that, but in RREF you want everything above and below your pivot positions to be 0
so in that case, you'd want the positon (row 2, column 3) to be a 0
lapis drift
yes, you want that to be a zero
lapis drift
yes
slow swan
Ok bet