clear all, close all
x=[12 41 93 147 204 264 373 509 773];
y=[930 815 632 487 370 265 147 76 17];
p=polyfit(x,log(y),1);
fprintf('exponente a= %2.3f\n',p(1));
fprintf('coeficiente c = %3.3f\n',exp(p(2)));

hold on
plot(x,y,'ro','markersize',4,'markerfacecolor','r')
z=@(x) exp(p(2))*exp(x*p(1));
fplot(z,[x(1),x(end)])
xlabel('x')
ylabel('y')
grid on
title('Regresión exponencial')
hold off