Question

Hi. Could someone please explain to me how to Graph Exponential Functions, preferably this one EXAMPLE: 7Log(3x)=15 solve for x.

Answer 1

I am assuming a common log, i.e., base 10. There is more than one approach, but I would probably isolate the log by dividing by 7, and then using the definition of log to convert to an exponential form.

Answer 2

\[\log(3x)=\frac{ 15 }{ 7 }\]

Answer 3

thats how you would graph it?

Answer 4

To graph you would normally have two variables; in this case there is no second variable such as a y. I was working towards solving for x.

Answer 5

could you explain to me step by step how to graph and solve it..... if thats not to much to ask please?

Answer 6

let's work on solving for x first. Again, I am assuming that we have common log (base 10).

Answer 7

yes

Answer 8

wait I had a typo

Answer 9

ok

Answer 10

use \[y=\log_{b}x<=> b ^{y}=x \]in this case we have\[10^{15/7}=3x\]

Answer 11

then just divide both sides by 3\[x=\frac{ 1 }{ 3 }*10^{15/7}\]

Answer 12

ok, i see

Answer 13

This is an exact solution for x, and we can use it graph it.

Answer 14

so i just use that? how does that work?

Answer 15

it graphs just like any other relation that has the variable y, but the axes are rotated 90-degrees. usually an exponential function of this form staring with "y =" would roughly look likebut...