Matlab - Anlamadığım Kısımlar (Yardımcı Olabilecek Var mı?)

Function h = pyt(a, b) 
  h = sqrt(a.^2 + b.^2);

??? Input argument "a" is undefined. 
   
  Error in ==> pyt at 2 
  h = sqrt(a.^2 + b.^2 );

%The program in File HELLO greets you and asks for your name. Then it 
  %greets you by name and tells you the date. 
  disp('Hello! Who are you?') 
  name = input('Please enter your name enclosed between quotes '); 
  d = 17-09-2014 ; 
  answer( 'Hello ' name ', Today is ' d ' .']; 
  disp(answer)

??? Error: File: Hello.m Line: 6 Column: 18 
  Unexpected MATLAB expression.