%%% a)
x = input("Give value for x: ");
f = (exp(x)+exp(-x))/2 -1;
printf("%g\n", f);

%%% b)
x = linspace(-10,10,101);
f = (exp(x)+exp(-x))/2 -1;
plot(x, f, 'r-');

%%% c)
r = linspace(-5, 2, 101);
x = 10.^r;
f = (exp(x)+exp(-x))/2 -1;
loglog(x, f, 'r-');