Since we are dealing with a limit of the form ∞∞, we can apply L'Hopital's Rule. L'Hopital's Rule states that if limx→cg(x)f(x) is of the indeterminate form 00 or ∞∞, then limx→cg(x)f(x)=limx→cg′(x)f′(x), provided the limit exists. Let f(n)=n100 and g(n)=en. Then f′(n)=100n99 and g′(n)=en. We have limn→∞enn100=limn→∞en100n99. We can apply L'Hopital's Rule repeatedly. After applying it 100 times, we get:
limn→∞enn100=limn→∞en100!. Since 100! is a constant and en goes to infinity as n goes to infinity, we have: limn→∞en100!=0. Alternatively, using L'Hopital's rule k times on limn→∞enn100, where k≤100 limn→∞enn100=limn→∞en100(99)(98)…(100−k+1)n100−k. limn→∞enn100=limn→∞en100!=0.