inverse:
y
=
x
+
4
2
which is a function.
Explanation:
If
y
=
2
x
−
4
then
XXX
y
+
4
=
2
x
and
XXX
x
=
y
+
4
2
Remember that
x
and
y
are arbitrary place holders and we could substitute any other variables in their place.
e.g.
x
=
y
+
4
2
⇔
s
=
t
+
4
2
however,it is common to express equations of this type with
y
as the "dependent" variable (that is
y
=
some expression based on the "independent" variable "x").
In this case we would write:
XXX
y
=
x
+
4
2
Note that since this generates a single value for
y
for any specific value of "x", this expression is a function.
