Basic Examples 
(7)
 

Find the stationary points of a function of one variable:
In[17]:=
statPoints=
[◼]
StationaryPoints
[t^2Exp[-t^2],{t}]
Out[17]=
Minima{{0,{t0}}},Maxima
1

,{t-1},
1

,{t1}
Plot the function and its stationary points found above:
In[22]:=
Plot[t^2Exp[-t^2],{t,-5,5},EpilogJoin[{Red,PointSize@Large},Point[{#〚2,1,2〛,#〚1〛}]&/@Flatten[Values[statPoints],1]]]
Out[22]=
-4
-2
2
4
0.1
0.2
0.3
———
Findthestationarypoints
of a periodic function:
In[19]:=
[◼]
StationaryPoints
[Sin[x],{x}]
Out[19]=
Minima-1,x
1
2
π(-1+4

1
) if

1
∈
,-1,x
1
2
π(3+4

1
) if

1
∈
,Maxima1,x
1
2
(π+4π

1
) if

1
∈

In[20]:=
[◼]
StationaryPoints
[Sin[x]Cos[x]-Tan[x],{x}]
Out[20]=
Inflection0,x
2π

1
if

1
∈
,0,x
π+2π

1
if

1
∈

———
Findthestationarypoints
of a function over a restricted domain:
In[22]:=
[◼]
StationaryPoints
[{Sin[x],-4<=x<=4},{x}]
Out[22]=
Minima-1,x-
π
2
,Maxima1,x
π
2

In[23]:=
[◼]
StationaryPoints
[{Sin[x]Cos[x]-Tan[x],-10<=x<=10},{x}]
Out[23]=
Inflection{{0,{x0}},{0,{x-3π}},{0,{x-2π}},{0,{x-π}},{0,{xπ}},{0,{x2π}},{0,{x3π}}}
———
Find stationary points of a function of two variables:
In[25]:=
[◼]
StationaryPoints
[(3x+1)y^3+x^2y,{x,y}]
Out[25]=
Saddle-
16
75
15
,x-
2
5
,y-
2
15
,
16
75
15
,x-
2
5
,y
2
15
,{0,{x0,y0}}
———
Find stationary points of a function of three variables when restricting to a plane:
In[26]:=
[◼]
StationaryPoints
[{xyz,x+y+z==100},{x,y,z}]
Out[26]=
Saddle{{0,{x0,y0,z100}},{0,{x0,y100,z0}},{0,{x100,y0,z0}}}
———
Using the "Type" option will return only stationary points of the given type:
In[34]:=
[◼]
StationaryPoints
[-x^4+15x^2+1+-y^4+15y^2+1,{x,y},"Minima"]
Out[34]=
{{2,{x0,y0}}}
In[35]:=
[◼]
StationaryPoints
[-x^4+15x^2+1+-y^4+15y^2+1,{x,y},"Maxima"]
Out[35]=

229
2
,x-
15
2
,y-
15
2
,
229
2
,x-
15
2
,y
15
2
,
229
2
,x
15
2
,y-
15
2
,
229
2
,x
15
2
,y
15
2

In[23]:=
[◼]
StationaryPoints
[{Exp[x]Sin[y],x^2+y^2==1},{x,y},"Type""Minimum"]
Out[23]=
{{-1.32116,{x0.673612,y-0.739085}}}
———
Using
Automatic
as the second argument gives an
Association
of all stationary points:
In[39]:=
[◼]
StationaryPoints
[-x^4+15x^2+1+-y^4+15y^2+1,{x,y},Automatic]
Out[39]=
Minima{{2,{x0,y0}}},Maxima
229
2
,x-
15
2
,y-
15
2
,
229
2
,x-
15
2
,y
15
2
,
229
2
,x
15
2
,y-
15
2
,
229
2
,x
15
2
,y
15
2
,Saddle
233
4
,x0,y-
15
2
,
233
4
,x0,y
15
2
,
233
4
,x-
15
2
,y0,
233
4
,x
15
2
,y0

Properties and Relations 
(2)
 


Possible Issues 
(2)
 
