Which of the following functions f(x,y,z) can be expressed as a transformation using homogeneous coordinates (i.e. f(x,y,z)=Axyz1, for some 4 by 4 matrix A). If it is possible compute the matrix A, else explain briefly why it is not possible. a) f(x,y,z)=x+y+1y2x+1 b) f(x,y,z)=3x5z+yx23z+5