Wednesday 8 January 2020

What's the formula to solve summation of logarithms?



I'm studying summation. Everything I know so far is that:



$\sum_{i=1}^n\ k = \frac{n(n+1)}{2}\ $



$\sum_{i=1}^{n}\ k^2 = \frac{n(n+1)(2n+1)}{6}\ $




$\sum_{i=1}^{n}\ k^3 = \frac{n^2(n+1)^2}{4}\ $



Unfortunately, I can't find neither on my book nor on the internet what the result of:



$\sum_{i=1}^n\log i$.



$\sum_{i=1}^n\ln i$.



is.




Can you help me out?


Answer



By using the fact that $$\log a + \log b = \log ab $$ then



$$ \sum^n \log i = \log (n!) $$



$$ \sum^n \ln i = \ln (n!) $$


No comments:

Post a Comment

real analysis - How to find $lim_{hrightarrow 0}frac{sin(ha)}{h}$

How to find $\lim_{h\rightarrow 0}\frac{\sin(ha)}{h}$ without lhopital rule? I know when I use lhopital I easy get $$ \lim_{h\rightarrow 0}...