1)
[tex]\it a_n=n^2-n=n(n-1)\\ \\ a_{n+1}=(n+1)n\\ \\ \dfrac{a_{n+1}}{a_n}=\dfrac{(n+1)n}{n(n-1)}=\dfrac{n+1}{n-1}>1 \Rightarrow (a_n)_{n\geq1}\ strict\ cresc\breve{a}tor[/tex]
[tex]\it 2)\ f(x)=x^2+2x+1=(x+1)^2\geq0\ \ \ \ \ (*)\\ \\ (f\circ g)(x)=f(g(x))=f(x-2009)\ \stackrel{(*)}{=}\ (x-2009+1)^2=(x-2008)^2\geq0[/tex]
