Zbadaj monotoniczność ciągu : [latex]a_{n} = n^{2} +2[/latex] [latex]a_{n} = frac{1-2n}{n} [/latex] prosze, pomóżcie ;c

[latex]a) \a_n=n^2+2\a_{n+1}=(n+1)^2+2=n^2+2n+2+2=n^2+2n+4\a_{n+1}-a_n=n^2+2n+4-n^2-2=2n+2 extgreater 0 ciag rosnacy[/latex] [latex]b)\ a_n= frac{1-2n}{n}\a_{n+1}= frac{1-2(n+1)}{(n+1)}= frac{-1-2n}{n+1}\a_{n+1}-a_n=frac{-1-2n}{n+1}-frac{1-2n}{n}= frac{n(-1-2n)-(n+1)(1-2n)}{n(n+1)}=\= frac{-n-2n^2-n+2n^2-1+2n}{n(n+1)}= frac{-1}{n(n+1)} extless 0 ciag malejacy [/latex]