Which one of the following is not true?

A. log2 8 = 3
B. log2 1 = 0
C. log2 2 = 1
D. log2 1/8 = -3
E. log2 (-1) = 1/2

1 Answer
Jul 9, 2018

The answer is E.

Explanation:

Log of a negative number is undefined,

Hence log_2 (-1) is Undefined.

The answer is E.

Other explanation:

log_2 (8) = log_2(2)^3 = 3log_2(2) = 3 -> A is True

log_2 (1) = 0 -> B is True. This is a basic log rule.

log_2(2) = 1 -> C is True. This is a basic log rule

log_2 (1/8) = log_2(1) - log_2(8)

= 0 - log_2(2)^3 = 0-3log_2(2) = 0-3 = -3 -> D is True