Please check the solution of this question and please tell what has been done in the 6th step (counting from the very start). How does sigma from 2 to infinity changes to sigma from 1 to infinity and why is lemda multiplied and how does the x-1! term becomes x!?
Hi I think you want to know how poison for for lambda forem has been converted into labmda (1-e-lambda)?? If yes, then we have used just the expansion of e-lambda. the poisson function is lambda ^x e-lambda/xfact Expand the series from 1 and convert into e-lambda Using e^lambda=1+labmda+labda^/2fact Try to solve yourself and you would get it Let me know if there is any other step you were referring to
