Question

help plz.question following

Answer 1

let X1 and X2 be independently and have joint density

\[f(x) = \left\{ e ^{-x } , x > 0\right\}\]

Let Y1 = X1 + X2 and Y2 = X1.Show that random variables Y1 and Y2 are independent

Answer 2

Y1 = -X1+X2 ??

Answer 3

\[Y _{1}=X _{1}+X _{2}\]

Answer 4

http://en.wikipedia.org/wiki/Probability_density_function#Independence
how do you write \(f(x)\) as \( f(x,y) \)

Answer 5

perhaps this article will help
http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&sqi=2&ved=0CGMQFjAB&url=http%3A%2F%2Fwww.stat.ucla.edu%2F~dinov%2Fcourses_students.dir%2F04%2FSpring%2FStat110A.dir%2FSTAT110A_notes.dir%2FPPCh05.pdf&ei=Q96oT6m2OszjrAfhreXmAQ&usg=AFQjCNFEI1ELELHgkL8dhNc69ZfYSqARpw&sig2=3yVAaxEcGUWafVdgERHIwA

Answer 6

can't understand ,i think it has to do with the transformation technique

Answer 7

I tried my best!!