Question 118946
for a quadratic of the form ax^2+bx+c, the equation for the axis of symmetry is x=-b/2a


in this case 9=-(-6b)/(2*2) __ 36=6b __ 6=b


looking at the quadratic formula can help to clarify
___ the formula gives two solutions {{{(-b+sqrt(b^2-4ac))/2a}}} and {{{(-b-sqrt(b^2-4ac))/2a}}}


the average of the two solutions (which is the midline of the graph) is -b/2a
__ the square root portions cancel each other