Question 542429
A quadratic functions whose vertex is (3,7) can be written (in vertex form) as
{{{f(x)=a(x-3)^2+7}}}
If it passes through (5,-9), {{{f(5)=-9}}}, so
{{{a(5-3)^2+7=-9}}} --> {{{4a+7=-9}}} --> {{{4a=-16}}} --> {{{a=-4}}}
{{{f(x)=-4(x-3)^2+7}}} <---> {{{f(x)=-4x^2+24x-29}}}