Answer :
Notice the minus sign in front of x^2==> Maximum
Then, find the vertex:
x_vertex = 2/(-2)=-1, and the corresponding f(x) is
f(-1)=-1+2-4 = -3
Maximum at (-1,-3)
Then, find the vertex:
x_vertex = 2/(-2)=-1, and the corresponding f(x) is
f(-1)=-1+2-4 = -3
Maximum at (-1,-3)