my problem e ^x= ∑n=0 ∞ * x ^n\ n ! but this program didn't work . it gives infinity error and I don't know how to use it. invalid range and called from errors

function [S] = yanital(x,y)
  T=0;
  for n=0:inf
    nf=1;
    for i=1:n
      nf=nf*i;
      T=T(x^n/nf)
      S=T;
    endfor
  endfor
endfunction

Answer 1

[KSSV]

n = 20 ;    % can be changed 
x = pi ;    % value of x 
y = 0 ;     % intilaize the required value 
for i = 0:n
  y = y+x^i/factorial(i) ;
end
[exp(x) y]