[tex]a_{n} = -4n+3\\\\a_{n+1} = -4(n+1)+3 = -4n-4+3 = -4n-1\\\\r = a_{n+1}-a_{n} = -4n-1 - (-4n+3) = -4n-1+4n-3 = -4\\\\r < 0, \ to \ ciag \ jest \ malejacy[/tex]
