= limx→-∞ 100/[-√( 1+ 100/x^2)- 1]
= 100/[-√( 1+0)- 1]
=-50;
2. the first picture: limx →∞ e * (1+1/x) (-x)-1= e * (1/e)-1= 0,
That is, e * (1+1/x) (-x)-1is infinitesimal,
-e ln [e * (1+1/x) (-x)]-1is infinitesimal,
e^x- 1~x，
——》e^ln[e*( 1+ 1/x)^(-x)]- 1~ln[e*( 1+ 1/x)^(-x)]；
The second picture: I don't understand it either.