A = [1 2 5 3 8]

[3 6 11 6 20]

[1 3 6 0 16]

[6 12 23 12 40]

[5 11 22 9 40]

Hi there i'm really struggling to find the determinant of this matrix using row operations

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- Jun 16th 2008, 01:44 PMmichael11Row operations on a matrix
A = [1 2 5 3 8]

[3 6 11 6 20]

[1 3 6 0 16]

[6 12 23 12 40]

[5 11 22 9 40]

Hi there i'm really struggling to find the determinant of this matrix using row operations - Jun 16th 2008, 02:27 PMflyingsquirrel
- Jun 16th 2008, 03:00 PMmichael11
hi,

i tried to finish it and i got detA = -3408

don't think thats right some how - Jun 16th 2008, 03:07 PMflyingsquirrel
Wooo, that's a big number. :D

How did you expand ? - Jun 16th 2008, 03:10 PMmichael11
I multiplied the 4 through, then found the determinant using the lattice method?

but something tells me that is wrong - Jun 17th 2008, 01:09 AMflyingsquirrel
I assume that the lattice method is Sarrus' rule ?

Repeat the first two columns :

Now multiply the red numbers together, multiply the green numbers together, multiply the blue numbers together and add these three products. Let's call the result .

Same thing : multiply together the numbers of the same color (except black :D) and add the three products. Again, let's call the result .

As , the determinant is given by .

Hope that helps. - Jun 17th 2008, 12:57 PMSoroban
Hello, michael11!

I assumed that they wanted Row Operations all the way . . .

flyingsquirrel had: .

Terrific job with the colors, flyingsquirrel!

.