For a parabola y = ax^2 + bx + c, the vertex is given by the coordinates: (-b/2a , -(b^2 - 4ac)/4a)

The equation of the parabola given is : y = 3x^2-12x

substituting the values, the vertex is

(12/6 , -(144 - 0)/12)

=> (2 , -12)

**The vertex of y = 3x^2-12x lies at (2 , -12)**