Answer:
The (x,y) point of the vertex is usually labelled as:
Vertex = (h, k)
h = -b / 2a
k = ah^2 + bh + c
f(x) = -3x^2 + 12x -5
a = -3 b=12 c=-5
h = -12 / -6 therefore h = 2
k = -3*2^2 + 12*2 -5
k = -12 + 24 -5 therefore k = 7
Vertex (2, 7)
Source: http://www.1728.org/quadr3.htm
Step-by-step explanation: