title: matrix inside matrix when multiplying symbolic matrices
body: <p>In matlab, i'm trying to multiply symbolic matrices(size 3X3). The output shows matrix having some elements which are themselves matrices.
  why some of the elements are matrices?</p>
  
  <p>Example code:</p>
  
  <pre><code>syms a1 a2 a3
  F2 = [a1+0.0003 .0002 .0004; a2+.0003 .0005 .0003; a3+.0003 .0002 .0004];
  C2 = F2'*F2;
  K = C2^(16/57); 
  T = inv(K)*C2*inv(K);
  S = T - 0.5*T^2 + 0.33*T^3;
  </code></pre>