The vertex of a parabola is at (12,-4) and its axis of symmetry is vertical. One of the ￼x-intercepts is at (15,0)￼. What is the ￼x-coordinate of the other ￼x-intercept?
The x intercepts are symmetrical about the x coordinate of the vertex
The other x intercept is ( 12 - (15-12) ) = ( 12 - 3) = 9