Source: Extra Practice

Which of the following is equivalent to log_b a?

Options

Option A is correct

(log_c a) / (log_c b)

Option B

log_c (a - b)

Option C

log_c a * log_c b

Option D

log_a b

Explanation

This is the Change of Base Formula. log_b a = (log_c a) / (log_c b) for any positive base c ≠ 1. Option D is the reciprocal (1 / log_b a), and options B and C are common misconceptions about log properties that do not exist.