Question 81128
the vertex is on the axis of symmetry; the general equation of which is x=-b/2a ... in this case, x=-9/(-2), or x=4.5


so the x value for the vertex is 4.5 ... to find the y value, just substitute into the equation


{{{y=-(4.5^2)+9(4.5)-5}}} ... so y=15.25 ... vertex is (4.5,15.25)