Question

How do I graph log equations on a calculator?

Answer 1

Hey britt :)
Does your calculator have a \(\Large\rm \log(\) button?
or maybe a \(\Large\rm \ln(\) button?

These are the two types of logs that calculators use, base 10 and base e.

So in order to input a log equation into your calculator you need to use your `change of base` formula.

Answer 2

Example:\[\Large\rm f(x)=\log_5x\]\[\Large\rm f(x)=\frac{\ln x}{\ln5}\]Here is how you would input this example into the calculator:\[\Large\rm \ln(x)\div \ln(5)\]That is the same as log base 5 of x.

Answer 3

\[\log_{4}x+1 \]
What would I do for this?

Answer 4

the same but add one?

Answer 5

Mmmm yah good! Just toss a +1 onto the end!\[\Large\rm =\ln(x)\div \ln(4)+1\]Remember your change of base formula? :O I hope sooooo.

Answer 6

What if there is a negative?
\[-\log_{4}x \]

Answer 7

would i put it in front of both of them or just one?

Answer 8

Just one.
You're multiplying the whole thing by -1, once.
It'll be a little easier to put into the calculator if you put it front of the whole thing, the first one.

Answer 9

One more question :)
\[\log_{4}(x-1) \]

Answer 10

With the 1 inside of the log?
\[\Large\rm \log_4(\color{orangered}{stuff})=\ln(\color{orangered}{stuff})\div\ln(4)\]Same idea.
Just replace the first natural log contents with the stuff that you started with.

Answer 11

\[\Large\rm \log_4(\color{orangered}{x-1})=\ln(\color{orangered}{x-1})\div\ln(4)\]