Quick math question, why's this false ...If f(x)=x^2 and g(x) =sq.root (x+3) then f(g(x)) is defined for all x

I am having difficulty understanding why, could someone please explain it to me?Quick math question, why's this false ...If f(x)=x^2 and g(x) =sq.root (x+3) then f(g(x)) is defined for all x
F(x)= x+3 is definied for all x





But f(g(x)) only is definied when g(x) is definied (by definition) --%26gt;


f(g(x))=x+3 only where x%26gt;=-3





Saludos.