Is $\log_{\cos x}(1)$ defined at $x=0+2k\pi$?
8061
Why must the base of a logarithm be a positive real number not equal to 1?
6571
A Challenging Integral $\int_0^{\frac{\pi}{2}}\log \left( x^2+\log^2(\cos x)\right)dx$
39747
Showing that $\lim_{x\to 0} x\log{x}= 0$ without using L'Hopital's rule
24716
$\int_0^\infty\frac{\log x dx}{x^2-1}$ with a hint.
126959
Prove $ \frac{1}{x+1} \le \ln(1+\frac{1}{x}) \le \frac{1}{x}$ with usage of the definition of a logarithmic function
114195
Evaluating $\int_0^\infty \frac{\log (1+x)}{1+x^2}dx$
118324
Other challenging logarithmic integral $\int_0^1 \frac{\log^2(x)\log(1-x)\log(1+x)}{x}dx$
145521
Why does $\arctan(x)= \frac{1}{2i}\log \left( \frac{x-i}{x+i}\right)+k$?
39752
Is there a limit of $\cos(n!)$?
108007
Can anybody help me with this logarithm problem?
91955
Integral of $\int\frac{1}{\log x}dx$
144633
Verification of proof involving logarithms and limits
149341
Help me evaluate $\int_0^1 \frac{\log(x+1)}{1+x^2} dx$
82321
Is $\cos(x) \geq 1 - \frac{x^2}{2}$ for all $x$ in $R$?
828
Computing the integral of $\log(\sin x)$
133279
Does $\lim_{n\to\infty}\underset{n}{\underbrace{\cos(\cos(...\cos x))}}$ exist?
158730
Is $\ln(\ln(n))$ irrational for any integer $n>1$?