Oblicz granicę: [latex] lim_{n o infty} frac{ pi }{2} * n * arctg(n)- frac{1}{2} ln |n^2 + 1|[/latex]

Oblicz granicę: [latex] lim_{n o infty} frac{ pi }{2} * n * arctg(n)- frac{1}{2} ln |n^2 + 1|[/latex]