Answer: B
We need to find the limit:
n→∞lim(1−n1)2n
Using the standard limit identity limn→∞(1+nx)n=ex, we can rewrite the expression as:
[n→∞lim(1−n1)n]2
Substituting x=−1 into the identity gives:
n→∞lim(1−n1)n=e−1
Therefore, the limit is:
(e−1)2=e−2
Thus, the correct option is B.