Log base 2 key strokes.

1. Sep 14, 2007

starchild75

1. The problem statement, all variables and given/known data
2^x=1500. solve for x. I need to know the key strokes on my scientific calculator. If I push log, it assumes log base 10. I need base 2.

2. Relevant equations

3. The attempt at a solution

2. Sep 14, 2007

bob1182006

do you know of a formula that can be used to "change bases" for logs?

3. Sep 14, 2007

starchild75

I don't recall it. Can you give it to me? Is there no way to find the log base 2 on a calculator?

4. Sep 14, 2007

bob1182006

If i remember right it's
$$log_b a = \frac{log_k a}{log_k b}$$
Where k is the base you're going to. In this case it would be base 10 so just log in your calculator.

5. Sep 14, 2007

starchild75

What do you put in place of a and b?

6. Sep 14, 2007

starchild75

I got that to work. I figured it out. Thanks a lot. It just seemed like there was a way to figure that out on a calculator but I can't remember for sure.

Starchild