Science & Mathematics - 28 November 2006

Consider f(x,y) = ((x^2)y)/((x^2)+(y^2)) (x,y) not equal (0,0)
0 (x,y) = (0,0)

find partial deriviatives at (0,0) using limits.

Ok.....heres my work....

fx(x,y) = [f(x+h,y) - (f(x,y))]/h --> after subing i get

fx(x,y) = ([0/h^2] - [0/0]) / h in turns gives me zero?


now y

fy(x,y) = [f(x,y+h) - f(x,y)] / h --> in turn gives me zero.

To me this doesnt seem right, am i right in assuming that 0/h^2 will give me zero. I know 0/0 is undefined but as we approach it are we approching 1 or zero or even infinity.

2006-11-28 06:13:53 · 3 answers · asked by Anonymous in Mathematics

2006-11-28 06:13:36 · 2 answers · asked by itsme 1 in Medicine

if many companies like belevedere and the body shop dont test their prodcuts on animals then why do so many companies still test their products on animals?

2006-11-28 06:13:34 · 11 answers · asked by jenniferyoung1987 2 in Zoology

2006-11-28 06:11:23 · 2 answers · asked by peyman a 1 in Engineering

At a very loud rock concert you measure the sound level at 120 dB. A jack hammer typically operates at a sound level of 92 dB. How many times more intense is the sound at the rock concert in comparison to the jack hammer?

2006-11-28 06:09:50 · 3 answers · asked by Missy 1 in Physics

This question isn't about creation or evolution, just strictly the big bang theory. Hasn't it even among scientist pretty much been proven false? I have read so many things by scientist who believe in evolution, and even they say that it isn't relavant anymore. If it isn't right, then why are people still going with it? I am not trying to get people angry, honestly just looking for an answer. Even if I am wrong that is OK, that is why I am asking because I don't know. I want real answers people.

2006-11-28 06:08:36 · 16 answers · asked by Hi 2 in Astronomy & Space

solve

(a) V=(P+w^2) / L

(b) If V=8, L=2, P=10 and G=0.35, find w.

please show working

2006-11-28 06:08:13 · 4 answers · asked by Anonymous in Mathematics

2006-11-28 06:08:10 · 1 answers · asked by webitgrl 2 in Astronomy & Space

5x - 2y = 10
3x + 2y = 6

Please can someone advise how to do this. I DONT JUST WANT AN ANSWER. I wanna understand how it was done.

2006-11-28 06:05:37 · 7 answers · asked by Perfect-Angel84 2 in Mathematics

I need to know what animals/plants live in Papua New Guinea, the quicker the response, the better. Please help!

2006-11-28 06:05:18 · 2 answers · asked by Lt. V 2 in Zoology

Pat has $3.20 in quarters, dimes and nickels. shehas the same number of each kind of coin. Find the Number of each kind of coin Pat has Solve algebraically

please show working

2006-11-28 06:04:53 · 1 answers · asked by Anonymous in Mathematics

Could someone please give step by step working on how to do these?

Solve:
14/x = 5/3(x-18.5)

Along with

Simplify:
(x+2)/x - (x-4)/x^2


Thanks!

2006-11-28 06:04:20 · 3 answers · asked by Tribomb 1 in Mathematics

I opened a packet of cheese last week and left it lying on my table whereby the temperature is approximately 27 degrees celsius. However I was astonished today when I opened the cheese to find out that a portion of it had become white and there were lots of thin white creatures moving about on the cheese. I was really shocked and I went straight on Yahoo answers to ask you to give me an explanation on the presence of these creatures. Alsorelate it to the ingredients of cheese so I understand it better. These creatures are made of what exactly and how do they form on cheese???

2006-11-28 06:04:08 · 5 answers · asked by Y L 2 in Other - Science

2x +4y = 8
-5x +3y = 5

Can anyone help remind me how to do this. I DONT NOT JUST WANT AN ANSWER. I want to understand how to do it

2006-11-28 06:03:37 · 8 answers · asked by Perfect-Angel84 2 in Mathematics

Sketch: http://img68.imageshack.us/img68/4919/trapezoidle6.jpg

2006-11-28 06:03:24 · 3 answers · asked by James S 1 in Mathematics

2006-11-28 06:03:14 · 6 answers · asked by Anonymous in Biology

2006-11-28 06:02:18 · 4 answers · asked by yoyo 2 in Chemistry

http://www.youtube.com/watch?v=KOuepCImKiU

2006-11-28 06:01:11 · 2 answers · asked by alex a 6 in Biology

For the reaction BaI2 + MgSO4 (aq)BaSO4 precipitates out.Calculate the percent yield (%)if11.083gof BaSO4precipitates when1.350Lof 0.0550 M BaI2 and1.200 Lof0.0476 M MgSO4(aq)are mixed.

2006-11-28 05:54:26 · 3 answers · asked by Anonymous in Chemistry

The taxi leaves every 15 min, the limo leaves every 28 mins, the bus leaves every 40 min, they never take a break from driving from the airport to the hotel

2006-11-28 05:53:00 · 4 answers · asked by Anonymous in Mathematics

please. i'm desperate.

2006-11-28 05:51:48 · 3 answers · asked by freeman 2 in Zoology

2006-11-28 05:50:54 · 6 answers · asked by Derek S 1 in Zoology

2006-11-28 05:49:49 · 6 answers · asked by shortstack 1 in Mathematics

I weighed out 0.2538g of pure ascorbic acid (F. Wt = 176.12g). I dissolved with <30mL of deionized water and added about 0.5 mL of diluted HNO3. Then I transfered it to a 50mL volumetric and diluted to volume. What's the concentration?

2006-11-28 05:49:10 · 3 answers · asked by slicksingh2k 2 in Chemistry

3y2-y-2

2006-11-28 05:49:02 · 3 answers · asked by guyana_bhai_2003 1 in Mathematics

How many grams of Al2(SO4)3 are needed to prepare 250.0 mL of a 0.400 M Al2(SO4)3 solution?

Details please...I havent learned this and my teacher just threw it in my face. Thanks!!

2006-11-28 05:47:32 · 5 answers · asked by Anonymous in Chemistry

2006-11-28 05:45:23 · 2 answers · asked by Anonymous in Engineering

Please give reasoning for your answer.

2006-11-28 05:45:03 · 4 answers · asked by Paul E 2 in Mathematics

Thanks you guys once again!!

2006-11-28 05:43:35 · 2 answers · asked by Anonymous in Chemistry

2006-11-28 05:43:26 · 10 answers · asked by Chase 1 in Biology