Geometric Random variables For k 1, P(X=klX >1)= P(X=k 2=1-p)k-1 2=_(1-p)k-1ๅซ (X>1) 2R2-2(1-p)k-1p 1 p(1-p)1-1-p =(1-p)k-2p=px(k-1) ·EXX>1]=โ=2k(X=kX>1) -ๅคp=+1p่ๅ
ฌn.+็ k=2 kไธ1 =1+E[X] 3Geometric Random Variables โข For ๐ > 1, ๐ ๐ = ๐ ๐ > 1 = ๐(๐=๐) ๐(๐>1) = (1โ๐) ๐โ1๐ (1โ๐) โ ๐โ1๐ ๐=2 = (1โ๐) ๐โ1๐ ๐(1โ๐)โ 1 1โ(1โ๐) = (1 โ ๐) ๐โ2๐ = ๐๐(๐ โ 1) โข ๐ธ ๐ ๐ > 1 = ๐๐ ๐ = ๐ ๐ > 1 โ ๐=2 = ๐๐๐(๐ โ 1) โ ๐=2 = (๐ + 1)๐๐(๐) โ ๐=1 = ๐๐๐(๐) โ ๐=1 + ๐๐(๐) โ ๐=1 = 1 + ๐ธ[๐] 3