Engineering mathematics

Question

If A is a non-zero column matrix of order n×1 and B is a non-zero row matrix of order 1×n then rank of AB equals ?

 

Rank(ab) can be zero???

Comments

your question is about column matrix $\times$ row matrix, not  row matrix $\times$ column matrix.

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@ankitgupta.1729

sorry, my mistake

 

Thank you

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Wrong multiplication

Answer 1

$A,B \ are\ non-zero\ matrices\ so\ matrix\ AB\ will\ be\ non-zero\ matrix$

$There\ will\ have\ at\ least\ one\ non-zero\ element.$

Answer 2

Rank (A*B) equals min of(rank of A, rank of B) therefore always 1.(since they are non zero Matrix)