# B How can log(x) = ln(x)/ln(10)?

1. Aug 7, 2016

### Natalinatul

Might be a silly question but I'm trying to search for ways to prove that it's right without using the numbers itself

2. Aug 7, 2016

### Staff: Mentor

Does the following equation make sense to you:
$$x=10^{log x}$$
It says that, by definition, the log of x is the power to which you have to raise 10 to get x.

3. Aug 7, 2016

Chestermiller's answer is correct, and so by this time you may have figured this out, but if you are still having difficulty, just google the proof of the change of base formula. Or just google the change of base formula, and many sites will also offer the proof (based on Chestermiller's hint)

4. Aug 7, 2016

### Natalinatul

Yup.. How could I miss that! The best thing about his answer was the fact he didn't answer it but gave a great hint... I figured it out now...

5. Aug 9, 2016

### Ssnow

Hi, there is this formula $\log_{a}{b}=\frac{\log_{c}{b}}{\log_{c}{a}}$ that permits to change the base from $b$ to $c$.

6. Aug 9, 2016

### Staff: Mentor

Don't you mean when you change the base from c to a?

7. Aug 9, 2016