- #1

Tenshou

- 153

- 1

##\left(a+b\right)^n## = ##\sum_{i=1}^{n}\dbinom{n}{k}a^{n}b^{n-k}##

and then you have the linear map ##\psi : A \rightarrow A## which is a derivation when;

##\theta(xy) = y\theta(x) + x\theta(y)## for all x,y in A

so the

*leibniz formula*for a ##\psi## derivation is

##\theta^n(xy)## = ##\sum_{k=1}^{n}\dbinom{n}{k}\theta^{n}(x)\theta^{n-k}(y)##

so does anyone have any idea why these two are very very similar if not the same? Also I am trying to understand how a Lie Algebra is a "Derivation"