Science & Mathematics - 18 December 2007

2007-12-18 00:16:04 · 7 answers · asked by Jameesha B 1 in Biology

2007-12-18 00:15:59 · 7 answers · asked by rohit p 1 in Mathematics

Hi,

I need to evaluate the integral of sin^3(2x)dx.

I started by using the power-reducing formula to turn sin^2 x into (1-cos 4x/2) and multiplying that by sin 2xdx.

So I have: ⌡ (1-cos 4x/2) (sin 2x) dx

Then I took the 1/2 out front to get:
1/2 ⌡ (1-cos 4x) (sin 2x) dx

Then I distributed the sin 2x out to get:
1/2 ⌡ (sin 2x - sin 2xcos4x) dx

Well, I wanted to use u-sub. with u = sin 2x and du = 2 cos 2x, but as you can see, I have cos 4x. How would I complete this problem (if I was on the right track in the first place)?

Thanks for the help! :>)

2007-12-18 00:15:48 · 6 answers · asked by LLH 2 in Mathematics

I like that one better than any others I've read about.... it just makes sense to me..... I really don't like the one that has the Universe expanding to death.... too unlike the natural laws we know.....who came up with the repeating theory, anyways?... thanks!!!

2007-12-18 00:09:18 · 5 answers · asked by meanolmaw 7 in Astronomy & Space

I recently became aware of a product that is claimed to be a globe that rotates (about 2 times a minute) using only light as an energy source. There are no batteries. Unfortunately this product is only sold in Japan in I can't find any information on it in English or anywhere that sells it in America. Has anyone heard of this or know how it works? The product's description says it was developed by "Shaw Y. Lin" and has several patents related to it.

Ideally I would like to find one of these sold for less than $500 (the price of the one on the site).

Here is the link (sorry japanese only)

http://www.beyes.jp/shop/fathersgarden/708741.php?no=1

2007-12-18 00:02:08 · 4 answers · asked by locksley 2 in Engineering