At x=2, the first term on the right has its minimum value of zero, making y maximum at 8. The vertex is therefore (2,8). All other values of x make this term negative which puts y always less than 8. When x>2, y behaves as y=-3x+14 or 14-3x. When x<2, y=2+3x or 3x+2. The two functions have opposite slopes which means that the linear functions are perpendicular, meeting at the vertex. There is symmetry on the left and right of the line x=2.