Suppose $a\neq 0$. Compute $\log_{8a} 4$ if $a = 1/4$.
log8a4$if$a=1/4
log 8(1/4) 4 =
log 2 4 = {use the change-of-base theorem }
log 4 / log 2 =
log 2^2 / log 2 =
2log 2 / log 2 =
2
