What is the vertex of the function f (x) = x2 + 3x + ?

The vertex of the function is at x = - 3/2. We cannot find the y value with an incomplete equation.

To find the x value of a vertex, we use the equation - b/2a, in which a is equal to the coefficient of x^2 (in this case 1) and b is equal to the coefficient of x (in this case 3).

-b/2a

-3/2 (1)

-3/2

This gives us that value. To find the y value, you would plug this into the equation. Since this equation is not complete, you cannot do that yet.