We know that
23 = 8, 32 = 9, 53 = 125, 70 = 1
In general, for a positive real number a, and a rational number m, let am = b,
where b is a real number In other words
the mth power of base a is b Another way of stating the same fact is
logarithm of b to base a is m If for a positive real number a, a ¹ 1
am = b,
we say that m is the logarithm of b to the base a