% numerikus integralas
n = 10
% integral formulabol leolvasva:
a = 2
b = 4
function y = f(x)
  y = exp(x-2) + x;
endfunction
% osztaskoz
h = (b-a)/10
% alappontok
x = a:h:b
% fuggvenyertekek
y = f(x)
%% trapez formula
T = 2 * sum(y) - y(1) - y(end);
T = T * h/2
% n =5-tel masik trapez formula az utolagos hibahoz
x_uj = x(1:2:end)
y_uj = y(1:2:end)
T_uj = 2*sum(y_uj) - y_uj(1) - y_uj(end);
T_uj = T_uj * h % h_uj = 2*h, h_uj/2 = h
hiba = abs(T - T_uj)