Science & Mathematics - 18 December 2007

Find where the slope is defined:

x^3 + y^3 = xy

Wouldn't it just be the following:

3x^2 + 3y^2*(dy/dx) = x*(dy/dx)+y

3y^2*(dy/dx) -x*(dy/dx) = -3x^2+y
(dy/dx)(3y^2-x) = -3x^2

so: (dy/dx) = (-3x^2 + y)/(3y^2 -x) ??

Thanks a lot, 10 pts to first correct answer

2007-12-18 14:28:58 · 3 answers · asked by Work Hard, Make Money, Enjoy Life... 3 in Mathematics

the lenght of a rectangle is 4ab. the width is 2ab. find the perimeter of the rectangle in terms of ab. please show work or at least enough to show me how to do it.

2007-12-18 14:25:28 · 5 answers · asked by Anonymous in Mathematics

They are both alexendrite , and they are from Russia , and our family has had them for a long time.

Here are the links to the pics:

http://i223.photobucket.com/albums/dd287/Annafur/DSCN4771.jpg

http://www.flickr.com/photos/13606906@N04/2122042618/

Thank you !

2007-12-18 14:25:24 · 3 answers · asked by A 5 in Earth Sciences & Geology

2007-12-18 14:21:53 · 1 answers · asked by purvish1997 2 in Mathematics

This problem on my assignment is giving me trouble

2007-12-18 14:17:13 · 6 answers · asked by Anonymous in Mathematics

Hind 111 recognizes a sequence of six nucleotides (AAGCTT) as a cut site. What are the odds that this sequence will occur in a random chain of DNA?

2007-12-18 14:15:34 · 3 answers · asked by Anonymous in Biology

Questions...
1. why it is important that Mendel began with pure bred plant?
2. How did Mendel's conclusion determined the biological inheritance?
3. What are Dominant & Recessive Alleles?

2007-12-18 14:14:35 · 3 answers · asked by Anonymous in Biology

To my understanding typhoons form somewhere around the western pacific ocean.

Why do typhoons form in the western pacific?
and
What areas of asia do typhoons effect?

2007-12-18 14:13:29 · 7 answers · asked by AC N 2 in Weather

2007-12-18 14:09:56 · 7 answers · asked by Marvie S 1 in Biology

I've seen many definitions but they all confuse me....
can someone put it simply?

2007-12-18 14:06:49 · 1 answers · asked by Anonymous in Biology

a. crossing-over.
b. independent assortment.
c. incomplete dominance.
d. pleiotropy.
e. codominance.

2007-12-18 14:04:34 · 1 answers · asked by Anonymous in Biology

if it isnt, the wat it the product of alcoholic fermentation?

2007-12-18 14:00:32 · 3 answers · asked by Kitten 2 in Biology

Also, what occurs in mitosis and cytokinesis....?

II Cell Cycle
-stages/correct order
-Interphase
-Time spent in each phase
-Synthesis of organelles
-Cyclin-prtein that regulate cell division
-Checkpoint
-G1

2007-12-18 13:59:09 · 1 answers · asked by Anonymous in Biology

A 45 kg girl is standing on a 150 kg plank. The plank, originally at rest, is free to slide on a frozen lake, which is a flat, frictionless surface. The girl begins to walk along the plank at a constant velocity of 1.5 m/s to the right relative to the plank.

A) what is her velocity relative to the surface of the ice?
B) What is the velocity of the plank relative to the surface of the ice?

I'm confused. I'm pretty sure I'm doing it right, yet I'm getting the wrong answer.
Here's what I'm doing:

M(girl)=45kg
M(plank)=150kg
V(girl)[initial]=0
V(plank)[initial]=0
V(girl)[final]=1.5
V(plank)[final]=?

M(girl)V(girl)[initial] + M(plank)V(plank)[initial] = M(girl)V(girl)[final] + M(plank)V(plank)[final]

So: 0 + 0 = (45)(1.50) + (150)(V)
So: 0 = 67.5 + 150(V)
So: 67.5 = -150(V)
So: V = -.45 <- Final Plank velocity.

So if the girl is moving 1.50 m/s, and the plank is moving -.45 m/s. Wouldn't her velocity relative to the ice be 1.50 - .45 = 1.05?

Book answers:
a) 1.15 m/s
b) -0.346 m/s

2007-12-18 13:58:52 · 2 answers · asked by mew1033 2 in Physics

for honors bio--
what kinds of foods or beverages are made form fermentaiton and what type of fermentation (lactic acid or alcoholic)
thanks!!

2007-12-18 13:58:43 · 3 answers · asked by Alexis 1 in Biology

2007-12-18 13:57:50 · 6 answers · asked by lord.belmont2007 2 in Geography

35. Which of the following statements is true?
A. Over 44 years passed from the first production of CFC's to the first awareness that they could cause environmental damage
B. CFC's are stable, odorless, nonflammable, nontoxic, and noncorrosive chemicals
C. CFC's are found in bubbles in styrofoam and insulation
D. CFC's are important because they help screen out ultraviolrt radiation from reaching Earths surface
E. CFC's remain in the troposphere because they are insoluble in water and chemically unreactive

2007-12-18 13:57:09 · 1 answers · asked by Tommey H 1 in Earth Sciences & Geology

like what should i look out for that lets me know when to use the ideal gas laws instead of combined gas law.

2007-12-18 13:56:51 · 1 answers · asked by Anonymous in Chemistry

write a balanced chemical equation when sodium & oxygen combine to form sodium oxide [Na2O]

2007-12-18 13:55:26 · 2 answers · asked by Anonymous in Chemistry

Ok help me out with these questions. These are due tomorrow with a bunch of other ones so i need all the help i can get. Thanks

1.Why is the constant temperature of boiling water on a hot stove evidence that boiling is a cooling process?

2.Will potatoes boiling in a pot of water cook faster if the water is boiling vigorously than if the water is boiling gently?

3. People who live where snowfall is common will attest to the fact thats air tempuratures are always higher on snowy days than on clear days. Some people get cause and effect mixed up when they say that snowfall cannot occur on very cold days. Explain.

4. On cold winter days the windows of your warm home sometimes get wet on the inside. Why is this so?

2007-12-18 13:55:01 · 3 answers · asked by varsitygurl 1 in Physics

a. the same locus on homologous
b. the same locus on heterologous
c. different loci on homologous
d. different loci on heterologous
e. the same locus on homologous mitochondrial

2007-12-18 13:54:32 · 3 answers · asked by Anonymous in Biology

I need to find an example of Nation, State,Nation-state.

2007-12-18 13:53:53 · 1 answers · asked by pounce 1 in Geography

2007-12-18 13:52:09 · 3 answers · asked by Jacklin 2 in Geography

Polars dissolve in polar and nonpolars in nonpolars. Can I get more details?

2007-12-18 13:50:39 · 2 answers · asked by sarah901167 2 in Chemistry

http://i59.photobucket.com/albums/g319/villiansk8er5148/5457.jpg

2007-12-18 13:49:45 · 7 answers · asked by Anonymous in Mathematics

Why won't it ignite?

2007-12-18 13:47:56 · 1 answers · asked by Anonymous in Physics

A locker combination system uses three digits from 0 to 9. How many different three-digit combinations with no digit repeated are possible? The Answers are 30, 504, 720, 1000. Which one is it? I said 504.

2007-12-18 13:47:25 · 6 answers · asked by Josh Kaz 3 in Mathematics

2007-12-18 13:47:17 · 1 answers · asked by ashlee 1 in Biology

anyone know?

i need it on miles

thx

:]

2007-12-18 13:47:16 · 5 answers · asked by gksjfakjfakjfakl 3 in Geography

which multiple choice answer is right


http://i59.photobucket.com/albums/g319/villiansk8er5148/4567.jpg

2007-12-18 13:45:47 · 3 answers · asked by Anonymous in Mathematics