y=3x^2-12x+7 What is the vertex?

You can find the answer:

1) by graphing

2) by completing the square

3) by using the formula:  -b/(2a) to get the x-coordinate:

    For this problem, a = 3 and b = -12   --->   -b/(2a)  =  -(-12)/(2·3)  =  12/6  =  2

    Now, replace 2 for x in the original function, to find the y-coordinate of the vertex.

    Then you will have your vertex.