Using functions for polynomials

Hello guys,

Im having trouble solving task 6 which is in the pdf file that I have shared.

This is what I have tried so far, but it's showing error message. I don't know how to carry on from this.

function ret=poly_fact(P1,P2)
a=size(P1)
b=size(P2)
orderP1=a(2)-1
orderP2=b(2)-1
for n=1:a(2)-1
   if orderP1==orderP2 | orderP1>orderP2
      if P1(1)==P2(1)
          for n=1:(a(2)-b(2))
            y=[0]
            P2=horzcat(P2,y)
         end
P1=P1-P2
      else
          d=P1(1)/P2(1)
          P2=P2*d
      end
   else
       disp('The order of P1 must be at least as high as the order of P2')
   end
end

Can anyone help me with task 6.

Thank you.

[dpb]

Well, you could show us what inputs you used and the error message for starters...