Science & Mathematics - 27 August 2007

Why when you multiply a complex nbr by its conjugate do you need absolute value signs? i.e

u*u(c) = |u|^2 - where u(c) is the complex conjugate of u (because I can't figur how to get the bar on top of the u!).

Obviously u*u=u^2, but what's the point of the abs value since a squared number is not negative?

I might be missing something blindingly obvious here......

2007-08-27 18:00:51 · 3 answers · asked by Anonymous in Mathematics

so here's the question...

Consider the phrase, "The quick brown fox jumped over the lazy dog." Which details of this situation would a physicist who is modeling the path of a fox ignore?


it's probably really easy. but im way tired. can anyone help?

2007-08-27 18:00:23 · 3 answers · asked by Monica 1 in Mathematics

2007-08-27 17:59:34 · 4 answers · asked by blanca r 1 in Earth Sciences & Geology

2007-08-27 17:55:45 · 6 answers · asked by Anonymous in Engineering

I am given sin 60 degree = (sq root 3) / 2, use the trig identities to find the exact values of

a) cos 30 degree

b) cos^2 60 degrees

c) sec (pi / 6)

d) csc (pi / 3)


please help and explain this to me, the book has a paragraph for an explain and does a crappy job at explaining it as well.

THANKS!

2007-08-27 17:55:31 · 4 answers · asked by Anonymous in Mathematics

It's like perma-dusk out tonight!

2007-08-27 17:49:50 · 11 answers · asked by Anonymous in Astronomy & Space

2007-08-27 17:48:45 · 14 answers · asked by Anonymous in Astronomy & Space

2007-08-27 17:45:27 · 6 answers · asked by Anonymous in Engineering

Find and then simplify the Difference Quotient for the following functions:

1. f(x) = 4x - 2
2. f(x) = 5/( x + 2)
3. f(x) = sqrt(2x - 3)

If at all possible, please work out the steps too. It wont do me much good to just have the answers. Its been a while since Ive had to do this.

2007-08-27 17:42:29 · 1 answers · asked by qwerty 2 in Mathematics

CAn u show me step By thep PLizz

2007-08-27 17:41:20 · 4 answers · asked by Paul Aka-Twinkie 1 in Mathematics

Math proble can u show me step bye step =D

2007-08-27 17:40:10 · 4 answers · asked by Paul Aka-Twinkie 1 in Mathematics

2007-08-27 17:38:48 · 5 answers · asked by DAVID P 1 in Mathematics

it already has been in a lab in Switzerland. What are the positives and negatives of creating it, if it can be done?

2007-08-27 17:35:11 · 6 answers · asked by Anonymous in Physics

2007-08-27 17:34:00 · 12 answers · asked by laken 1 in Geography

or has it already happened?
eastern standard time?

2007-08-27 17:32:56 · 8 answers · asked by jake p. 2 in Astronomy & Space

ok so I have to find the remaining 5 functions, I am given sin = (sq root 3) / 4

so a^2 +b^2 = c^2
a^2 + sq root 3^2 = 4^2
a^2 + 3 = 16
a = sq root 13

cos = sq root 13 / 4

tan = sq root 3 / sq root 13

csc = 4 / sq root 3

sec = 4 / sq root 13

cot = sq root 13 / sq root 3

did I do this correctly??

please help / explain if I didn't . . . thanks!!

2007-08-27 17:28:49 · 3 answers · asked by Anonymous in Mathematics

* = raised to the power of
Ok sooo it starts with (x+h)*3 - 2 - (x*3 - 2)

Then you cube the (x+h), right, and that ends up being

hx*3 + 2h*2x*2 = h*3x - 2 - x*3 + 2

So the twos cancel out and it's just

hx*3 + 2h*2x*2 = h*3x - x*3

right?

Oh yeah and this has all been over h

So the book has the answer as 3x*2 + 3xh + h*2
But I have no idea how...

Help?

2007-08-27 17:25:06 · 6 answers · asked by Anonymous in Mathematics

2007-08-27 17:24:01 · 3 answers · asked by Yner 3 in Astronomy & Space

Hello, I have a few problems for precalc that i dont really understand. Thanks for your help in advance
Find the Inverse:
1. f(x)=1/1+6
2. f(x)=3-x^2
Find the Function
f(x)=x^3-12x Max (___,____) Min (___,___)
The domain of the Function
f(x)=sqrroot x^2-49



I've looked in a text book, i've looked at all notes, and i reviewed what you said... however, i just enrolled into this school. i dont have notes going back that far and i hardly understand it. i dont know what im doing wrong but i really just need the answers.

2007-08-27 17:23:41 · 3 answers · asked by Anonymous in Mathematics

I'm thinking is this formula: (dy/dx) = (dy/dt)/(dx/dt), hence:
x(t) = 3t^2 + 2 = (dx/dt) = 6t
y(t) = 2t^3 - 1/2 = (dy/dt) = 6t^2, then plug in the respective values to the formula above: (6t^2/6t), am I on the right track? any hint is appreciated, thanks!

2007-08-27 17:15:50 · 3 answers · asked by Jorm 3 in Mathematics

I see many questions about the two moons and the red moon tonight. The way I understand it is that the planet Mars will be as close to the earth's orbit as it has been in over 2000 years, and because of this, and Mar's atmosphere, the sun's reflection will actually be bouncing from the sun to MARS, then off of Mars' dense atmosphere to earth. This light "detour" off of Mars will then cause the moon to turn a "blood red" color. But I'm cloudy as crap here so I won't be able to see anything anyway. I even broke out the telescope, apparently for nothing. And as far as the two moons...well it's actually the moon and mars in the sky, but Mars won't be any brighter than Venus is during the summer soltice. It will just look like the brightest STAR in the sky. Courtesy of "Star Hustler" circa 1990, PBS

2007-08-27 17:13:59 · 6 answers · asked by cakeypoo_24 3 in Astronomy & Space

2007-08-27 17:10:21 · 4 answers · asked by J_IC 3 in Astronomy & Space

If you knew everything about the past and present, could you use that information to predict the future? Basically what I'm asking is that are any actually randomness in the universe, or do we just see it as random because we can not collect enough data to understand it? Please explain your answer.

2007-08-27 17:05:09 · 12 answers · asked by ☢☠☣☢☠☣ 3 in Physics

why do males at age 14 have more blood cells than girls?

2007-08-27 17:01:04 · 4 answers · asked by sk8tergurl1405 3 in Biology

all you have is:

-a long pipe with a valve at the end that dispenses water in drops (buret)
- a meter stick

-clamps, ring stand etc (not important)

thats it, now confirm what we already know: acceleration due to gravity is -9.81 m/s/s

the problem for me is, there is no way to measure time, therefore we cannot find time or final velocity.

2007-08-27 16:59:03 · 4 answers · asked by Hi My Name is 2 in Physics

2007-08-27 16:54:43 · 5 answers · asked by schwaz 1 in Astronomy & Space

2007-08-27 16:51:38 · 3 answers · asked by Anonymous in Astronomy & Space

How often do they occur?

2007-08-27 16:47:31 · 7 answers · asked by Mrs. J 4 in Astronomy & Space

i looked online everything says a diffrent time any ideas?

2007-08-27 16:46:46 · 4 answers · asked by cathryn c 1 in Astronomy & Space

2007-08-27 16:36:46 · 6 answers · asked by Anonymous in Physics