Question

Given that this density function is valid, what properties must it satisfy?

Answer 1

\[f(y)=\frac{ \lambda^{y}e^{-\lambda} }{ y! } , y=0,1,2,.....\]

Answer 2

@eliassaab any idea?

Answer 3

Thinking I need to prove that the sum is equal to 1 and that the function can only take values between 0 and 1?