lim log(cos(x)) x->oo
lim log(cos(x)) pi x->--+ 2
-oo
= (-8.85294337322831 + 3.14159265358979j)
lim log(cos(x)) pi x->--- 2
= -8.85286596152862
(-8.85294337322831 + 3.14159265358979j)