Example problem
Contents
(a)
Consider the function f(x) = sin(x)-x. Let x=10^-7 and print out y=f(x) with 15 digits.
How many of these digits are correct???
x = 1e-7; y = sin(x) - x; fprintf('y = %.15g\n',y) % print y with 15 digits
y = -1.7205356741103e-22
(b)
Plot the function f(x) for x in [0,10^-7].
Why does the plot look like this???
x = linspace(0,1e-7,1000); % vector of 1000 equidistant points 0,...,1e-7 y = sin(x) - x; % vector of function values plot(x,y) % plot vector y vs. vector x xlabel('x') title('function sin(x)-x')