1 ------ -4 + x lim 4 x->4+
Limit(4^(1/(-4 + x)), x, 4)
oo
= -2.02711208311355e-72
1 ------ -4 + x lim 4 x->4-
0
= -5.76546433768738e-80
-2.02711208311355e-72