Question 907702
When {{{x=0}}},
{{{f(0)=be^(-(0+3))-a}}}
{{{f(0)=be^(-3)-a}}}
{{{f(0)=b/e^3-a}}}
When {{{x->infinity}}}, {{{e^(-(x+3))->0}}}, and {{{f(x)->-a}}}