Im trying to do this, but where I miss

[TRMP]

Define ext()=
Prgm
:Local fx,fy,fxx,fyy,f1,po,x,y
:Disp "Finding local max, min, and saddle points"
:Request "Type function",f1
:fx:=d/dx(f1,x)
:fy:=d/dy(f1,y)

Now how can I do
 
solve(system(f1=0,f2=0),{x,y}) and put in a two distinct variables
Would be with a matrices or a list?
And how to do?
Im not finish but I am not knowing where to go from here

TY for any help...


:Disp x
:Disp y
:
:
:
:Disp "Derivada parcial em relação a X: ",fx
:Disp "Derivada parcial em relação a Y: ",fy
:
:EndPrgm

[TRMP]

Not much progress but here we go:


Define sela()=
Prgm
:Local f,fx,fy,mat,fxx,fyy,a,fxxpo

©Where f-> function
©fx-> first derivative in terms of X
©fy-> first derivative in terms of Y
©mat->Trying to make extraction of coordinate point (x,y) to use in second derivative in terms of X with P0(x,y), doesnt work! Accept suggestion

©fxx and fyy second derivative in terms of respective var

©a to store coordinate point I really need HELP here! How can I use or put this two points in two different variables?



:Request "Funcao",f
:fx:=d/dx(f,x)
:fy:=d/dy(f,y)
:fxx:=d/dx(fx,x)
:fyy:=d/dy(fy,y)
©Add fxy:=d/dy(fx,x)
:a:=solve(system(fx=0,fy=0),{x,y})

:fxxpo:=solve(fxx=0,x)|a  ©Ok! i believe inst a good solution here if a get a "a" like this: x=−1 and y=−1 or x=0 and y=0 or x=1 and y=1 What im gonna do?
:mat:=newMat(1,2)
:mat[1,1]:=fx          ©Make a new line for description
:mat[1,2]:=fy
:
:
:Disp fx
:Disp fy
:Disp mat
:Disp fxx
:Disp fyy
:Disp a
:Disp fxxpo
:Disp x
:Disp y
:
:EndPrgm