Question

How to find the Summation from a function?

Answer 1

if the p. q is less than 1

q^2 / (1-sp)^2

i want to find P(X=n)

from \[\sum_{n=0}^{\infty} s^{n} P(X=n)\]

Answer 2

above summation is equal to q^2 / (1-sp)^2

Answer 3

\[\sum_{n=0}^{\infty} s^{n}P(X=n) = \frac{ q^2 }{ (1-sp)^{2} }\]