Kyle R. answered 12/12/17
Tutor
4.9
(31)
Mathematics and Science Tutor - Graduate Student
1. Factor to find the x-intercepts.
9x2 + 12x + 4
(3x + 2)(3x + 2)
3x + 2 = 0
3x = -2
x = -2/3
2. Find the axis of symmetry (x = -b/2a).
x = -b/2a
x = -12/18
x = -2/3
3. Use the equation for the axis of symmetry as the x-component of your vertex. Plug this value in to the initial equation to find the y-component of the vertex. Because there is only one x-intercept, you know this must be the vertex, so (-2/3,0) is the vertex.