Answer:
The recursive function in Python is as follows
def expo(nmber, exponent):
  power = exponent
  if power == 0:
    return 1
  if power %2 == 1:
    power = power - 1
    return nmber * expo(nmber, power)
  else:
    power = power/2
    return expo(nmber, power) ** 2
The time complexity is O(log(n))
Step-by-step explanation:
See attachment for complete program where comments are used for explanation.
The Time Complexity
The function is then called power - 1 times for odd exponents or power/2 times for even exponents before it reaches the base case.
As the exponent is divided by 2, for even exponents; it means that the function tends to log(n). log(n), in this case represents the base case.
Since the function is repeated, then the time complexity is: O(log(n))