Матлаб - всё подряд

организация цикла и вывод значений массива на экран:

 U = [];
 S = 0.5; 
for k = 1:1:10 
  S = S + 1/factorial(k); 
  U(k)=S;   
end;  
disp(U);
   // получим: 1.5000    2.0000    2.1667    2.2083    2.2167    2.2181    2.2183    2.2183    2.2183    2.2183

=====================
консоль:

                                                    |
Error: Unexpected MATLAB expression.
 
>> U = []; S = 0.5; n=10; for k = 1:1:10  U(k)=S;   end;  disp(u);
??? Undefined function or variable 'u'.
 
>> U = []; S = 0.5; n=10; for k = 1:1:10  U(k)=S;   end;  disp(U);
    0.5000    0.5000    0.5000    0.5000    0.5000    0.5000    0.5000    0.5000    0.5000    0.5000

>> U = []; S = 0.5; n=10; for k = 1:1:10   S = (1/pi)arcos(cos(10^n)*S); U(k)=S;   end;  disp(U);
??? U = []; S = 0.5; n=10; for k = 1:1:10   S = (1/pi)arcos(cos(10^n)*S); U(k)=S;   end;  disp(U);
                                                      |
Error: Unexpected MATLAB expression.
 
>> U = []; S = 0.5; n=10; for k = 1:1:10   S = (1/pi)arccos(cos(10^n)*S); U(k)=S;   end;  disp(U);
??? U = []; S = 0.5; n=10; for k = 1:1:10   S = (1/pi)arccos(cos(10^n)*S); U(k)=S;   end;  disp(U);
                                                      |
Error: Unexpected MATLAB expression.
 
>> U = []; S = 0.5; n=10; for k = 1:1:10   S = (1/pi)*arccos(cos(10^n)*S); U(k)=S;   end;  disp(U);
??? Undefined function or method 'arccos' for input arguments of type 'double'.
 
>> U = []; S = 0.5; n=10; for k = 1:1:10   S = (1/pi)*arcos(cos(10^n)*S); U(k)=S;   end;  disp(U);
??? Undefined function or method 'arcos' for input arguments of type 'double'.
 
>> U = []; S = 0.5; n=10; for k = 1:1:10   S = (1/pi)*arccos(cos(10^n)*S); U(k)=S;   end;  disp(U);
??? Undefined function or method 'arccos' for input arguments of type 'double'.