1. ## Probability distributions

What is the density function of X for x>0?

some of the steps are

Please can anyone show me step by step. I really don't understand. Thank you very much.

2. ## Re: Probability distributions

Hey imp120.

Have you tried differentiating each term in the series? Can you please show us your work?

3. ## Re: Probability distributions

Thank you very much.. I am a self learning , didn't go to school. Don't know what to do on this question.

4. ## Re: Probability distributions

Thank you so much for helping

5. ## Re: Probability distributions

Originally Posted by imp120
Since you are 'self-studding' it appears that your weakness is really in calculus.
That will make much of this impossible for you to follow.
$D_x(x^ke^{-x})=kx^{k-1}e^{-x}-x^ke^{-x}$ the $\large-$ comes from the derivative of $e^{-x}$.