# Thread: plus and minus logs

1. ## plus and minus logs

i can do the first one but the second one i cant seem to work it out

2. Originally Posted by realistic
i can do the first one but the second one i cant seem to work it out
What base are you working to? That is an important omission on your part. Note that, for a > 0, $\displaystyle 1 = \log_{a} a$ ....

3. Originally Posted by mr fantastic
What base are you working to? That is an important omission on your part. Note that, for a > 0, $\displaystyle 1 = \log_{a} a$ ....
thats how the question in the book is

log3−log10+1

wouldnt the answer just be log3?

4. Originally Posted by realistic
thats how the question in the book is
Well, if the base is 10 then you know that $\displaystyle \log 10 = 1$ and so the answer to the second question is plainly $\displaystyle \log 3$ since the 1's will cancel.

5. Originally Posted by mr fantastic
Well, if the base is 10 then you know that $\displaystyle \log 10 = 1$ and so the answer to the second question is plainly $\displaystyle \log 3$ since the 1's will cancel.
ah yeah i see that but was not sure thanks for explaining it out