Functions of one variable Graph of a function

graph of function f(x, y) = sin(x) · cos(y).

the graph of function.

f
(
x
)
=


{



a
,



if 

x
=
1
,




d
,



if 

x
=
2
,




c
,



if 

x
=
3
,








{\displaystyle f(x)={\begin{cases}a,&{\text{if }}x=1,\\d,&{\text{if }}x=2,\\c,&{\text{if }}x=3,\end{cases}}}

is

{
(
1
,
a
)
,
(
2
,
d
)
,
(
3
,
c
)
}
.



{\displaystyle \{(1,a),(2,d),(3,c)\}.\,}

the graph of cubic polynomial on real line

f
(
x
)
=

x

3


−
9
x



{\displaystyle f(x)=x^{3}-9x\,}

is

{
(
x
,

x

3


−
9
x
)
:
x

 is real number

}
.



{\displaystyle \{(x,x^{3}-9x):x{\text{ real number}}\}.\,}

if set plotted on cartesian plane, result curve (see figure).