Asked by Anonymous

Write the fraction you would use to change the base for log8 15 (base 6)
Answered by Anonymous
i meant base 8
Answered by Reiny
let x = log<sub>8</sub> 15
by definition: 8^x = 15
now take log of both sides, (base 10 is understood)
log (8^x) = log 15
x log 8 = log 15
x = log15/log8

in general: log<sub>a</sub> b = log b/log a , where a ≠ 1, a > 0