✔ 最佳答案
a = a^1
Therefore log (base a) a = 1
(this is true for any value of a : log(base 10) 10 = 1; ln e = 1; and so on)
If you raise a number to a power, then its logarithm is multiplied by that power, so
log a^a = 1 x a
and a log a^a = a (1 x a) = a^2
So you can look at alog(base a) (a^a) as (a^2)log a, ..... ..... (1)
or as log a^(a^2) ..... ..... ..... ..... (2)
(1) makes the equation (a^2) x 1 = 16
(2) makes the equation a^2 = 16 (but arrived at by a slightly different route - I thought I would give you both)
In either case, we have a^2 = 16, so a = 4
You should be able to finish it off now.