5 Show that the Signum Function f : R → R, given by
f x
x
x
x
( )
,
,
� ,
=
>
=
<



1
0
0
0
1
0
if
if
if
is neither one-one nor onto 6 Let A = {1, 2, 3}, B = {4, 5, 6, 7} and let f = {(1, 4), (2, 5), (3, 6)} be a function
from A to B