For unlimited access to Homework Help, a Homework+ subscription is required.
Note: I am not looking for the entire answer to this question:
A trough is filled with a liquid density of 840 kg/m3
The ends are equalateral triangles with a side length of 8m and the vertex at the bottom.
Find the hydrostatic force on one end of the trough.
I am wondering why the length of our sample strip is 8 - 2xi /Sqrt(3) . Or more specifically, how am I supposed to realize that we are subtracting our 2a from 8. Plugging in numbers I can see that it is true, but I would have never guessed that we needed to do that, any advice on what I should be looking for?
1. What is the area of the region bounded by the curves y = 2x^2 - 7 and y = 2/x between x=1 and x=3?
The answer I get, both by calculator and by hand, is 2ln(3) - 10/3. According to the test, it is 4ln(2) - 2ln(3) + 8. Even my calculator doesn't think that is equivalent.
This is from a Straighter Line test. They have been known to have some errors on their tests. If this is one of them, please inform me.
2. The second question is one I never really learned the way to do. I know how to get four points from it. But the rest of my methods seem convoluted. It is: what is the area of the parallelogram whose edges are the lines y = - 1/2 * x - 1, y = x + 2, y = - 1/2 x + 2, and y = x - 5/2. What is the way to do this? Or, is there a particularly efficient and quick way to do it?
These two questions are from Calculus I. I mention this in case it helps to contextualize what methods you would recommend I answer this with. The Straighter Line course I am taking is very bad in regards to presenting all the information you need to know--if fact, it doesn't--so I have had to pick up quite a few things on the side myself. I may not have learned what I am supposed to do with some of these situations. But, I think the first of the two questions may be the result of an error on the part of Straighter LIne.
Ah, so, thank you for any answers.
