<p>if matrix A has dimensions m<em>n and matrix B has dimensions n</em>p, where m, n, and p are distinct positive intergers, which of the following statements must be true?</p>
<p>I. The product BA does not exist.
II. the product AB exists and has dimensions m<em>p
III. the product AB exists and has dimensions n</em>n</p>
<p>A) I only
B) II only
C) III only
D) I and II
E) I and III</p>
<p>the correct answer is D, can anyone explain to me why is it D??</p>
<p>BA would be [n,p] x [m,n] the column of B and the row of A do not equal, so it cannot be multiplied together</p>
<p>The dimension of the product would be the row of A x the column of B.
so AB ([m,n]x[n,p]) is [m,p]
o_o</p>
<p>m is the row, n is the column</p>
<p>n is the row, p is the column?</p>
<p>eh… i never learned matrix before, confusing - -</p>
<p>well when multiplying matrices the inside numbers have to be the same in order to multiply.</p>
<p>M<em>N N</em>P, they both have N on the inside so they’re multipliable and have dimensions of the outer numbers M*P</p>
<p>for example, the matrix</p>
<p>-3 1
4 5
6 7</p>
<p>n is the 1,5,7?</p>
<p>when multiplying 3 matrices you have to assess them step by step. the first two are not multipliable so you stop there and say it can not be multplied</p>
<p>i think i get it - -</p>
<p>Matrix format: </p>
<p>Row * Column; </p>
<p>Since this multiplication is defined, the resultant matrix is of dimensions m * p; the matrix would have p columns.</p>