Function f(x) is called even function if f(x) = f(x) for every x from the function domain. A graph of even function is axis OY symmetrical to. Functions cos(x) or x^{2} are examples of even functions. Function f(x) is called uneven function if f(x) =  f(x) for every x from the function domain. A graph of uneven function is point of origin symmetrical to. Functions sin(x) or x^{3} are examples of uneven functions. Some functions are neither even nor uneven, x^{3}+1 as an example. If the function f(x) domain is the point of origin symmetrical then the function is a sum of even and uneven functions f(x) = f_{e}(x) + f_{u}(x). f_{e}(x) = [f(x) + f(x)]/2 f_{u}(x) = [f(x)  f(x)]/2 The model illustrates this theorem. You may insert a function into a text field f(x) and obtain its graph (blue) and graphs of corresponding even (red) and uneven (green) functions.
