I;m having trouble with some questions on exponential growth. All of them seem to end with the same type of equation, one that I cannot figure out.
They will; end something like this..
2=1.15^x (1.15 to the power of x)
On simpler questions like this, you had to find a common base.
ie. 27=3^x. 3^3=3^x therefore x=3
But I don't see how you can find a common base wth 2 and 1.15, or other such numbers (where one has many decimal places-for example, one question ended up as 9=1.076842^x).
The question that ended with 2=1.15^x was as follows: A bacteria grows at 15% per day. In how many days will it have doubled?
Anybody have any ideas?
Say we have the following:
That can be expressed as:
And to solve it on your calculator, simply type divided by
If the base of the log is not mentioned, it is assumed to be 10.