Can I break up $\log(a - b)$?

$\begingroup$

For constants $a$ and $b$, I know that I can break up $\log(a/b)$ into $\log(a) - \log(b)$.

Can I conveniently break up $\log(a - b)$ somehow into several terms?

$\endgroup$ 2

1 Answer

$\begingroup$

$$\log(a-b) = \log\left(a\cdot\left(1-\frac ba\right)\right)$$

$$= \log(a) + \log\left(1-\frac ba\right)$$

if $\displaystyle\left|\frac ba\right| \lt 1$ then it can be written as

$$= \log(a) -\sum_{n=1}^{\infty} \frac{x^n}{n}$$

Where $x=b/a$

$\endgroup$ 3

Your Answer

Sign up or log in

Sign up using Google Sign up using Facebook Sign up using Email and Password

Post as a guest

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

You Might Also Like