alright, so im like 99% sure im doing it right, yet getting an answer that apparently isnt right.

i need to find k.

and the set up is 1 = the integral from 0 to infinity of k*y*e^(-2y) (i know 1 b/c the area under the curve needs to equal 1)

and it says use by integration by parts.

so i said (ive tried it using both parts as u and v) u = e^-2y and v = y

with the k out to the side, and do uv - vdu i get 3e^-2y. plugging in infinity gets me 0 and then minus when u plug in 0 gets you -3. so -3k = 1. thus k = -1/3 . i tried checking my answer in the calc by using the f-int function but it def. isnt the right answer.

10/16/2007 10:03:35 PM

nvm i may have found my mistake

10/16/2007 10:13:59 PM

i love when explaining my problem to someone else leads me to the answer or my mistake. happens all the time in the physics tutorial center and they look at me like i'm nuts when it hits me mid-sentence.

10/17/2007 12:17:10 AM