Enter
f
(
x,y
) as a function of
x
and
y
:
f
(
x,y
)
=
Enter plot settings. The
y
settings can be either numbers or functions of
x
:
x
min:
y
min(# or
g
(
x
) ):
Grid (
x
) :
Axes:
x
max:
y
min(# or
g
(
x
) ):
Grid (
y
) :
Enter a candidate (
p,q
) for a critical point: (
p,q
) = (
,
). It produces as a red dot on the surface.