clear
format compact
format long

fs = @(x) cos(x);
fsd = @(x) -sin(x);

fm = @(x) (cos(x)).^3;
fmd = @(x) -3*(cos(x)).^2 .* sin(x);

x1 = 1;
itermax = 40;

help newton

xs = newton(fs, fsd, x1, itermax);
noft = length(xs)
err = xs(end) - pi/2

xm = newton(fm, fmd, x1, itermax);
noft = length(xm)
err = xm(end) - pi/2