house can someone explain to me how to find rank of matrix

Question

anonymous · Answer

There was a question like this on here earlier, u could look for it...

anonymous · Answer

no answer

anonymous · Answer

I found it here http://openstudy.com/groups/mathematics/updates/4e4806e50b8b8d00ebdcaeb5 Search with Google..

anonymous · Answer

The rank of a matrix is equal to the number of pivot columns in its reduced form

anonymous · Answer

what is pivot colum

anonymous · Answer

how can one find it

anonymous · Answer

Reduce the matrix. Once it's in reduced form, the pivot columns are the first non-0 column in a row (starting from the left)

$$\left[ \begin{matrix} 1 &3 & -5 & 14\ 0 & 2 & 7 & 0\ 0 & 0 &0 & 3 \end{matrix}\right] $$

So in this example, only columns 1, 2, and 4 are pivot columns.

anonymous · Answer

So the rank of this matrix is 3 (the number of pivot columns)