Question 1061303
{{{f(x)=a(x+1)(x-3)^2}}}
When {{{x=2}}}, 
{{{f(2)=a(2+1)(2-3)^2=6}}}
{{{a(3)(1)=6}}}
{{{a=2}}}
So,
{{{f(x)=2(x+1)(x-3)^2}}}