Question

How would you change the base formula to rewrite a expression using common logarithms?

log(base7)8

Answer 1

Just do it? \(\log_{7}(8) = \dfrac{\log(8)}{\log(7)}\)

Answer 2

\(\bf \textit{log change of base}\implies log_ab=\cfrac{log_{\color{red}{ c}}b}{log_{\color{red}{ c}}a}\)

Answer 3

So is the base always on the bottom of the fraction

Answer 4

yes
and "c" could be any number really, so long is the same above and below

Answer 5

ahh okay, i get it. But can i ask one more question?

Answer 6

ok

Answer 7

ok 1 second

Answer 8

1

Answer 9

hehe

Answer 10

lol, how would you write this as a single logarithm.

log\[\log_{5}4 +\log_{5}3 \]

Answer 11

http://www.chilimath.com/algebra/advanced/log/images/rules%20of%20exponents.gif <-- notice the 1st rule there

Answer 12

Oh ok so would it be \[\log_{5} (4x3) \] ?

Answer 13

yeap

Answer 14

:D ahh alright thank you you!

Answer 15

yw