3: The limit algebra shows that the answer depends on the number (a − 1). There are three possibilities, two of them can be done using the limit algebra (when a − 1 is positive or negative). The third, a − 1 = 0, needs some work, since ∞⁰ is an indeterminate power. Fortunately, here this can be worked out just by going back a bit, no tricks are needed.

The answers are:

Answer