Simplifying ln: A Calculus Struggle

Tweedybird
Messages
3
Reaction score
0

Homework Statement



Simplify
ln [(e^1-3ln2)/(2∏/e)]

Homework Equations



I was using the equation e^lnx = x to try and simplify the numerator, but I am unsure if that is correct.

The Attempt at a Solution



I am very rusty with my calculus and when it comes to using ln, I tend to get stumped with the question.
I had simplified the numerator to -5 using e^lnx = x, but I was very unsure if this is correct; I may be making up rules of my own.
The denominator was simplified to 2∏(e^-1)
The entire fraction was then ln (-5/(2∏(e^-1)) and I couldn't figure out what to do next with this.
 
Last edited:
Physics news on Phys.org
Tweedybird said:

Homework Statement



Simplify
ln [(e^1-3ln2)/(2∏/e)]

Homework Equations



I was using the equation e^lnx = x to try and simplify the numerator, but I am unsure if that is correct.

The Attempt at a Solution



I am very rusty with my calculus and when it comes to using ln, I tend to get stumped with the question.
I had simplified the numerator to -5 using e^lnx = x, but I was very unsure if this is correct; I may be making up rules of my own.
The denominator was simplified to 2∏(e^-1)
The entire fraction was then ln (-5/(2∏(e^-1)) and I couldn't figure out what to do next with this.
Hello Tweedybird. Welcome to PF !

If what you have is indeed
\displaystyle \ln \left(\frac{e^1-3\ln(2)}{2\pi/e}\right)​
then you are very far off.

Perhaps you meant
\displaystyle \ln \left(\frac{e^{1-3\ln(2)}}{2\pi/e}\right)\ .​

Well ... there's still a problem.
 
SammyS said:
Hello Tweedybird. Welcome to PF !

If what you have is indeed
\displaystyle \ln \left(\frac{e^1-3\ln(2)}{2\pi/e}\right)​
then you are very far off.

Perhaps you meant
\displaystyle \ln \left(\frac{e^{1-3\ln(2)}}{2\pi/e}\right)\ .​

Well ... there's still a problem.


The second one is exactly the question I need help with! Sorry for the confusion, but I'm not sure why there is a problem with it, it is in my textbook as a question to be simplified!
 
Tweedybird said:
The second one is exactly the question I need help with! Sorry for the confusion, but I'm not sure why there is a problem with it, it is in my textbook as a question to be simplified!
Review properties of logarithms & exponents.

One property that you may find helpful is:
\displaystyle \ln\left(\frac{A}{B}\right)=\ln(A)-\ln(B)​
 
SammyS said:
Review properties of logarithms & exponents.

One property that you may find helpful is:
\displaystyle \ln\left(\frac{A}{B}\right)=\ln(A)-\ln(B)​

I figured the question out! A little review and that hint helped me out quite a bit! Like I said in my post, I am a little rusty with this subject! Thank you for your help :)
 
There are two things I don't understand about this problem. First, when finding the nth root of a number, there should in theory be n solutions. However, the formula produces n+1 roots. Here is how. The first root is simply ##\left(r\right)^{\left(\frac{1}{n}\right)}##. Then you multiply this first root by n additional expressions given by the formula, as you go through k=0,1,...n-1. So you end up with n+1 roots, which cannot be correct. Let me illustrate what I mean. For this...
Back
Top