ncsu919 All American 1067 Posts user info edit post |
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 |