That is, something like:
f(x) = f(x+c)
c is an arbitrary constant. Examples:
How might I get grapher to chart this or select an appropriate tool to visualize these functions?
Yes, indeed it can:
Square wave: try something like
y = (-1)^round(x)(but with proper formatting). Something like
y = (round(x+0.5) - round(x)) - 0.5 would also work.
Sawtooth wave: try something like
y = x mod 1 or, more elaborately,
y = 2((x-0.5) mod 1) - 1. However, something like
y = x - round(x) would also work. If you don't like any of these, try something like
y = x - floor(x).
The triangular wave is left as an exercise to the reader ;-)
Of course, you can also use the truncated Fourier series, but that may be too wiggly for your taste.