Varius piecewise continuous functions. The unit step function can be created using the sign (+ or -) of x as follows: u(x) = 0.5[ sign(x) + 1] = 0.5*(1+1) = 1, for x>0 u(x) = 0.5*(-1+1) = 0, for x<0.

Use the mouse wheel (or the scroll bars) to view content (e.g. function definitions). Click on the buttons next to each function to hide (or display) it. Study and look at the definition of each function (note the color scheme), in particular how the unit step function u(t-a) is used. Adjust the height A of function f_1, the left point a and the right point b of the square wave function u(t-a) - u(t-b). Use the mouse arrow to adjust these values. If it does not respond or show an arrow then move the mouse to the top of the page just to the right of the contents (1,2,3,4,5) until you see the hand on the blue arrow. Click one or two times on the blue arrow (the hand).