# Homework Help: Density Functions - Oceanography

1. Feb 17, 2010

### xr250h

1. The problem statement, all variables and given/known data

http://img39.imageshack.us/img39/3143/calcquiz3.jpg [Broken]

The writing says: A(x)=int(p(y),y=0..x) <-- Maple format

2. Relevant equations

A(x)=int(p(y),y=0..x)

3. The attempt at a solution

So I did not attend class the day we went over this and he only went over it that day. I honestly have no idea how to even go about doing it, but here's a stab in the dark:

I believe the "water column" he is talking about is a rectangular prism with length=1 m, width=1 m, and height=50 m.

The density function is p(x)=10 cod per cubic meter (where p is "rho" and x is an area?)

a. Total number of cod in water column- Wouldn't this be the area of the column * 10?

So, A=LWH=50 m^3. 50*10=500 cod. Also, this is the same answer I would get if I took the Area under the curve p(x)=10 from x=0..10.

For the other functions, would I take the area under the curve as well?

b. Depth where fish density is largest - Would this be the maximum point on the graph? If so, the first one would be 0<x<50 because the density of fish is constant.

c. Number of cod between 20 and 30 meters - Simply the area under the curve from 20 to 30?

Any help is much appreciated!

Thanks,
Ryan

Last edited by a moderator: May 4, 2017