Solve Exponentials Problem: ln((V+v)/(V-v)) = 2ctV

  • Thread starter Thread starter Nevermore
  • Start date Start date
Nevermore
Messages
10
Reaction score
0
I have ln((V+v)/(V-v)) = 2ctV, and I've checked this is right. But how do I go from here to v = V((e^Vct - e^-Vct)/(e^Vct+e^-Vct))? The solutions just give them as successive lines.

(I appreciate that's not the easiest thing to read, it's taken from the 2004 MEI specimen paper for A-level Mechanics 4, if that helps.)
 
Mathematics news on Phys.org
HINT: Laws of logs;

\ln\frac{a}{b} = \ln|a| - \ln|b|
 
OK, so
ln((V+v)/(V-v)) = 2ctV
=> ln(V+v)-ln(V-v) = 2ctV
ln(V)ln(v) - ln(V)/ln(v)
2ln(v) = 2ctV
v = e^Vct

Is this right? Where can I go from here?
 
Nevermore said:
OK, so
ln((V+v)/(V-v)) = 2ctV
=> ln(V+v)-ln(V-v) = 2ctV
ln(V)ln(v) - ln(V)/ln(v)
2ln(v) = 2ctV
v = e^Vct

Is this right? Where can I go from here?

there is something wrong in what u have written... first of all
log(a*b) = log(a) + log(b)...what u have used is log(a+b) = log(a) * log(b)..even after that u have written something wrong...check it once more...
anyway u don't need to use that...use the basic definition of logs...
if ln(a) = b
=> e^b = a
 
In other words,
\frac{V+v}{V-v}= e^{2ctV}
Solve that for v.
 
Insights auto threads is broken atm, so I'm manually creating these for new Insight articles. In Dirac’s Principles of Quantum Mechanics published in 1930 he introduced a “convenient notation” he referred to as a “delta function” which he treated as a continuum analog to the discrete Kronecker delta. The Kronecker delta is simply the indexed components of the identity operator in matrix algebra Source: https://www.physicsforums.com/insights/what-exactly-is-diracs-delta-function/ by...
Fermat's Last Theorem has long been one of the most famous mathematical problems, and is now one of the most famous theorems. It simply states that the equation $$ a^n+b^n=c^n $$ has no solutions with positive integers if ##n>2.## It was named after Pierre de Fermat (1607-1665). The problem itself stems from the book Arithmetica by Diophantus of Alexandria. It gained popularity because Fermat noted in his copy "Cubum autem in duos cubos, aut quadratoquadratum in duos quadratoquadratos, et...
I'm interested to know whether the equation $$1 = 2 - \frac{1}{2 - \frac{1}{2 - \cdots}}$$ is true or not. It can be shown easily that if the continued fraction converges, it cannot converge to anything else than 1. It seems that if the continued fraction converges, the convergence is very slow. The apparent slowness of the convergence makes it difficult to estimate the presence of true convergence numerically. At the moment I don't know whether this converges or not.

Similar threads

Back
Top