Science & Mathematics - 26 December 2006

1. sin(pi/2+y) + sin (pi/2+[-y])= 2 cos y

2. sin (x+pi/2) / cos(x+pi/2)= -cot x

3. sin ( 90 degrees+y)+sin(-3 pi/2 -y) = 0

4. cos(y-3pi/2)= -sin y

5. sin (x-y) / sin x sin y =tan x - tan y

2006-12-26 04:34:58 · 2 answers · asked by Anonymous in Mathematics

2006-12-26 04:34:03 · 9 answers · asked by porcha b 1 in Mathematics

2006-12-26 04:32:29 · 2 answers · asked by XtremeGuy 1 in Engineering

2006-12-26 04:31:26 · 11 answers · asked by kieran_kai_jay 1 in Mathematics

I need help solving this equation step by step pls.

x + 1/x+1 = 4

2006-12-26 04:31:20 · 8 answers · asked by SHIBZ 2 in Mathematics

if general relativity deals with acceleration then why the fuss over super strings [ie. gravtons]

2006-12-26 04:29:58 · 5 answers · asked by mrg5834 1 in Physics

If women get big hips to support children then why do men get broad shoulders?

2006-12-26 04:29:51 · 6 answers · asked by Luekas 4 in Biology

Plaster of paris using mould making purpose.The mould quickly
damaged.We should avoid this problem how to solve or try to another
one mix some percentage in the POP MOULD get SOME strength in some level.

2006-12-26 04:28:44 · 1 answers · asked by VENKATARAMAN K 2 in Engineering

3. What is the mass of one (1) mole of carbon dioxide, CO2?
4. What is the mass of one (1) mole of sulfuric acid, H2SO4?

Find the number of moles in each quantity
5) 3.00 g H2SO4
6) 12.0 CH4
7) 3.40 X 10-1 g CaO
8) 13.4 g SO2

Find the mass of each substance

9) 0.369 mol N2
10) 10.0 mol Ca(NO3)2
11) 1.94 x 10-3mol C6H12O6
12) 0.0112 mol KCl


Convert between moles and particles. Particles can be atoms, ions, or molecules.
Calculate how many particles are in the following and place the answers in the work
assignment. Don't forget to use Avogadro's number!
13) 25.9 mol Fe
14) 0.30 mol NaCl 2

Calculate the number of moles in each of the following and place the answers in the work
assignment.
15) 47 x 1023 atoms Cu 1
6) 8.30 x 1025 molecules H2O



I dont understand these I have plenty more to do but I jus need help with these for right now can someone help me with a few?

2006-12-26 04:28:40 · 7 answers · asked by queenpravato 1 in Chemistry

2006-12-26 04:27:41 · 3 answers · asked by Anonymous in Biology

i need to write a chemistry on the theme "safety in the lab" and i really need help.....i need to know which chemicals are dangerous, wat are the consequences, how to store those chemicals and work withe them, the first aid when someone gets hurt (include: bases ,acids, salts, gasses, metals.....)

please help me, give some links and thanks

2006-12-26 04:27:03 · 3 answers · asked by CosmicLove 5 in Chemistry

2006-12-26 04:25:58 · 2 answers · asked by John C 1 in Chemistry

2006-12-26 04:22:15 · 17 answers · asked by porcha b 1 in Mathematics

Simplify:
sqrt(252x^5)

I came up with 6x^2*sqrt7x

2006-12-26 04:21:08 · 5 answers · asked by badmf777 1 in Mathematics

greater or equal than 3 balls.
what goes through your brain when juggling and how can, if ever, a robot learn this?

2006-12-26 04:19:43 · 2 answers · asked by dannyp 1 in Engineering

2006-12-26 04:19:30 · 2 answers · asked by Anonymous in Physics

Be sure to check your solutions (tell if any of them are extraneous):
sqrt(3x + 4) + x = 8
This what I have so far, but I'm stuck.
sqrt(3x +4) + x = 8
sqrt(3x + 4)^2 = (x+8)^2
3x+4 = x^2 -16x + 64

-60 = x^2 -19x
Where do I go from here or am I way off track?

2006-12-26 04:16:28 · 12 answers · asked by badmf777 1 in Mathematics

(Note: When you integrate sin x you get -cos x which is even)

2006-12-26 04:14:06 · 3 answers · asked by suba k 1 in Mathematics

do i have to move the decimal to the left 33 times?

2006-12-26 04:13:16 · 9 answers · asked by Anonymous in Mathematics

2006-12-26 04:13:08 · 9 answers · asked by Anonymous in Mathematics

Any suggestions ?

2006-12-26 04:12:44 · 6 answers · asked by Stephanie Lynn 1 in Mathematics

2006-12-26 04:12:04 · 1 answers · asked by suba k 1 in Mathematics

3x-5y=y-mx

2006-12-26 04:11:38 · 15 answers · asked by kieran_kai_jay 1 in Mathematics

if I was to reverse, would the "time" i'm in make me younger or would the time around me be only thing reversed? even though a theoretical 4th Dimension, equations can still be manipulated to comply, but would the conformation include me or just around me?

2006-12-26 04:11:10 · 5 answers · asked by Anonymous in Physics

Its been 6 years sine the third and im really sure of that!

2006-12-26 04:08:23 · 4 answers · asked by Sam H 2 in Zoology

How can you calculate the answer of any number(16 in this case) raised to any power(198 here) quickly and easily without cumbersome failure-prone multiplication? Particularly in this case, at least how can we calculate the last two digits? Does anyone know a straight formula?

2006-12-26 04:07:23 · 7 answers · asked by dynamicronnie 1 in Mathematics

I live in ohio and i just looked at the 15 day forecast and there is no snow insight!!! Will it ever come?!

2006-12-26 04:06:50 · 10 answers · asked by Anonymous in Weather

2006-12-26 04:05:06 · 1 answers · asked by Anonymous in Medicine

I would like to be able to separate water into oxygen and hydrogen (hydrolysis), then collect the oxygen and hydrogen for combustion and reconstitution into water. I would like to use a catalyst to lower the amount of energy needed to separate the components. Anyone help?

2006-12-26 04:04:30 · 5 answers · asked by buffed_n_shy 1 in Chemistry

2006-12-26 04:00:37 · 7 answers · asked by just4fun f 1 in Chemistry