(1)
(2)
lim(2n-√4n^2+an+3)*(2n+√4n^2+an+3)/(2n+√4n^2+an+3) n→∞,
=lim(4n^2-4n^2-an-3)/(2n+√4n^2+an+3)
=-a/4=1 , a=-4