A population of 15 items. 4 red, 6 black and 5 green. a sample of 4 items are selected. what is the probability that the sample contains 3 black and 1 green?
1. Prove by recurrence that
so n ∈ N and θ ∈ R
(cos (nθ)+isin (nθ)=cos (nθ)+isin (nθ)
2. Prove that U_(n+1) =(1/5)(U_n ^2 +6) and
U_1 =(5/2), is decrease