HP 49g+ - Manual (Page 513)

Page 16-39
The resulting graph is shown below for k = 5 (the number of elements in the
series is 2k+1, i.e., 11, in this case):
From the plot it is very difficult to distinguish the original function from the
Fourier series approximation. Using k = 2, or 5 terms in the series, shows not
so good a fitting:
The Fourier series can be used to generate a periodic triangular wave (or saw
tooth wave) by changing the horizontal axis range, for example, from –2 to 4.
The graph shown below uses k = 5:
Fourier series for a square wave
A square wave can be generated by using the function




< <
< <
< <
=
4 3 , 0
3 1 , 1
1 0 , 0
) (
x if
x if
x if
x g