please help this linear algebra questions with steps ,thanks

(5) (15 points) The function f(x, y, z) is defined as f (x, y, z) = (x - 2)2 + ( y + 1)2 + 22 + 2(2 - 2) (y + 1) -2(2 - 2)z - 2(y + 1)z. (i) (9 points) Find a symmetric matrix A such that x- 2 f ( x , y, z ) = ( x - 2 y + 1 zA y + 1 Z (ii) (6 points) Does there exist real numbers x, y, z such that f(x, y, z)