For example,
A=[4 5 6 7; 8 4 5 6; 4 5 6 8; 8 4 8 9 ;1 2 2 4; 4 5 6 8]; % A matrix
v = [4 5 6 8]; % vector you are searching for
[flag,locs] = ismember(A,v,'rows'); % flag gives logical true for each row if v is equal to corresponding row of A
locations = find(flag); % if you want to get exact location such as 3rd row, 5th row and if you are using with rows option, use this.
