ParametricPlot
@8
x
@
t
D
, y
@
t
D<
,
8
t, 0, 8
p
<
,
AxesLabel
>
8
"x"
,
"y"
<
,
AspectRatio
>
Automatic,
PlotStyle
>
88
Thickness
@
0.01
D
, Red
<<D

20

10
10
20
x

20

10
10
20
y
Extend the values of the parameter
t to see more of the spiral:
ParametricPlot
@8
x
@
t
D
, y
@
t
D<
,
8
t, 0, 16
p
<
,
AxesLabel
>
8
"x"
,
"y"
<
,
AspectRatio
>
Automatic,
PlotStyle
>
88
Thickness
@
0.01
D
, Red
<<D

40

20
20
40
x

40

20
20
40
y
Bull's eye.
B.2) Parametric plots of curves in three dimensions
When you plot in two dimensions, you use two coordinate axes:
h
=
5;
spacer
=
h
10
;
twodims
=
Graphics
@8
Line
@88

h, 0
<
,
8
h, 0
<<D
,
Text
@
"x"
,
8
h
+
spacer, 0
<D
,
Line
@88
0,

h
<
,
8
0, h
<<D
,
Text
@
"y"
,
8
0, h
+
spacer
<D<D
;
Show
@
twodims, PlotRange
>
All
D
x
y
To plot a point, you specify an
8
x, y
<
coordinate:
8
x, y
<
=
8
2, 3
<
;
Show
@
twodims,
Graphics
@8
Red, PointSize
@
0.03
D
, Point
@8
x, y
<D<D
,
PlotRange
>
All
D
x
y
To plot in three dimensions, you need three coordinate axes:
h
=
5;
spacer
=
h
10
;
threedims
=
Graphics3D
@8
8
Blue, Line
@88

h, 0, 0
<
,
8
h, 0, 0
<<D<
,
Text
@
"x"
,
8
h
+
spacer, 0, 0
<D
,
8
Blue, Line
@88
0,

h, 0
<
,
8
0, h, 0
<<D<
,
Text
@
"y"
,
8
0, h
+
spacer, 0
<D
,
8
Blue, Line
@88
0, 0,

h
<
,
8
0, 0, h
<<D<
,
Text
@
"z"
,
8
0, 0, h
+
spacer
<D<D
;
Show
@
threedims, PlotRange
>
All, Boxed
>
False
D