Question

Y=3x^2+30x+81 What is the vertex of this

Answer 1

(-5,6) is the vertex.

I did this by using the vertex x coordinate Formula which is -b/2a

So in this case a=3 b=30 c=81

So if put the number in it would be
-30/2(3) = -30/6 = -5
Now that we know the x coordinate of the vertex which is -5. You plug the x of -5 into the quadratic equation to get the y.

3(-5)^2 + 30(-5) + 81=y

Simplify it

75-150+81= Y

Combine the light terms

6=y

So the coordinate points are (-5,6)