kill(all)$

van=facebook.com/LearningCalculus$

M(theta):=
matrix(
    [cos(theta),-sin(theta),0],
    [sin(theta), cos(theta),0],
    [         0,          0,1])$

P(x,y):=[x, y, 0];

T:M(theta).P(x,y);

f(x,y):=x^x=y^y$

F(x,y,theta):=''(f(T[1][1],T[2][1]))$

F(x,y,theta);

F(x,y,0);
F(x,y,%pi*3/4);