Bài 9

def luy_thua(a, n):
    if n == 0:
        return 1          # truong hop co so: bat cu so nao mu 0 = 1
    if n < 0:
        return 1 / luy_thua(a, -n)   # xu ly so mu am
    return a * luy_thua(a, n - 1)     # goi lai

a = float(input("Nhap co so a: "))
n = int(input("Nhap so mu n: "))

ket_qua = luy_thua(a, n)
print(f"De quy: {a}^{n} = {ket_qua}")
print(f"Kiem tra: {a}**{n} = {a**n}  ({'Dung' if round(ket_qua,9)==round(a**n,9) else 'Sai'})")