Question

log(base 4) 1/8=

Answer 1

-1.5

Answer 2

It's been a while since I do log stuff, but I know that \[ 2^3 = 8 \] can be written as \[ log_2\; 3 = 8 \]

So I can rewrite your question as \[ 4^x = \dfrac18 \]; which is equal to \[2^{2x} = 2^{-3} \]
2x = -3, x = -1.5