How do you evaluate log_(1/4)( 1/64)log14(164)?

1 Answer
Sep 11, 2016

log_(1/4) (1/64) = 3log14(164)=3

Explanation:

In log format like this one, the question being asked is

"To what power/index must 1/414 be raised to give 1/64164?"

OR: "How can I make 1/414 into 1/64164 using an index?"

4^3 =64, :. (1/4)^3 = 1/64

Clearly the answer is 3.

log_(1/4) (1/64) = 3

OR rarr Log form and index form are interchangeable:

log_a b= c " " hArr" " a^c=b

log_(1/4) (1/64) = x" " hArr " " (1/4)^x = 1/64

x=3

It will be a distinct advantage in your work with logs and indices if you know all the powers of the numbers from 1 to 10 (up to 1,000) by heart.

Ie up to 10^3 =1,000