Question 1109710
{{{a<0}}} so the vertex is between x of 1 and 5; in fact vertex will be  (3,8).


{{{a(x-1)(x-5)>0}}}


{{{f(x)=a(x-1)(x-5)}}}
{{{a(3-1)(3-5)=8}}}
{{{a*2*(-2)=8}}}
{{{a=-2}}}



Function is  {{{highlight(-2(x-1)(x-5))}}}


{{{graph(300,300,-2,8,-2,8,-2(x-1)(x-5))}}}