# Thread: geometric moment generating function

1. ## geometric moment generating function

hi guys,
i guess this is a basic question but you calculate the first and the second moment from this formula:

mx(t) = ((1/10)e^t)/(1-(9/10)e^t)

i think i'm missing some crucial part of this thing.

thanks

2. Originally Posted by jamborta
hi guys,
i guess this is a basic question but you calculate the first and the second moment from this formula:

mx(t) = ((1/10)e^t)/(1-(9/10)e^t)

i think i'm missing some crucial part of this thing.

thanks
You evaluate the first and second derivatives at t = 0 (assuming you mean moments about the origin).