# How do you evaluate #log_(1/2) 5# using the change of base formula?

##### 1 Answer

Sep 16, 2017

#### Answer:

I got:

#### Explanation:

Consider a log such as:

we can change into the new base

as you can see the new base gives a fraction between two new logs BUT we can easily use our calculator to evaluate

in our case:

[I forgot, you can test your result by applying the definition of log:

we got that:

so:

that can be evaluated with the calculator]