MapleMaxMinEx.mws

12.9 #6

>    P:=32*x*y^2-x^2*y^2-x*y^3;

P := 32*x*y^2-x^2*y^2-x*y^3

>    Px:=diff(P,x);

Px := 32*y^2-2*x*y^2-y^3

>    Py:=diff(P,y);

Py := 64*x*y-2*x^2*y-3*x*y^2

>    solve({Px=0,Py=0});

{y = 0, x = x}, {x = 0, y = 32}, {x = 8, y = 16}

>    eval(P,{x=8,y=16});

16384

12.9 #10(similar)

>    V:=(100*x*y-3*x^2*y^2)/(4*x+4*y);

V := (100*x*y-3*x^2*y^2)/(4*x+4*y)

>    Vx:=diff(V,x);

Vx := (100*y-6*x*y^2)/(4*x+4*y)-4*(100*x*y-3*x^2*y^2)/(4*x+4*y)^2

>    Vy:=diff(V,y);

Vy := (100*x-6*x^2*y)/(4*x+4*y)-4*(100*x*y-3*x^2*y^2)/(4*x+4*y)^2

>    solve({Vx=0,Vy=0});

{y = -10/3, x = -10/3}, {y = 10/3, x = 10/3}

>    eval(V,{x=10/3,y=10/3});

250/9

>