The reciprocal function is:
#f(x)=1/x#
It's graph is as following:
This is an example of asymptote.
Since #x# can take all values except #0# for #f(x)# to be defined,
Domain: #R-{0}#, i.e., all real numbers except 0.
Range: #R-{0}#, i.e., all real numbers except 0.