Science & Mathematics - 31 December 2007

Is this an odd or even function? Explain please

f(x) =

x
-------------
(x^2 -1)

x^2 -1 is an even function

x is an odd function

and when you sub in f(-x), you cant turn it into an even or odd function, which is expected, as it is neither

However, when you graph the function, it turns out as an odd function, which came to a big surprise to me

I though that if we broke down x^2 -1 into (x-1)(x+1), and then try it, the -1's still cancel each other out, as if they'd been squared, and when you actually sub the values in for f(x), it does form an odd curve!

The equation is saying its neither and the graph is saying its odd! Punch it in a program and you'll see xD... ='(

I'm lost. Either I'm forgetting something or I didn't understand odd and even's when I did them a while back.

Can somebody explain this, because I aint gonna sleep till I get this.... lol xD - 2 am here

2007-12-31 01:58:55 · 8 answers · asked by Suki 4 in Mathematics

Consider a gold nucleus and an alpha particle. They exert an electrostatic repulsive force F on each other and are separated by distance r. The particle and the nucleus are being treated as point charges. when r = 5x10^-14m, F= 16N, and when r = 20x10^-14m, F = 1N. Use this information to calculate the values of the forces at distances r = 10x10^-14m and 15x10^-14m.

I'm really stuck on this one, can anyone help?

2007-12-31 01:53:34 · 5 answers · asked by Anonymous in Physics

2007-12-31 01:48:32 · 2 answers · asked by willow 6 in Earth Sciences & Geology

http://en.wikipedia.org/wiki/SMOT

I know it doesn't work, I know there is no such thing as free energy but what is the actual practical reason why smots don't work.

Gravity wheels and such have been shown why they really don't work, but I still haven't seen anyone explain why a smot fails.

2007-12-31 01:38:09 · 6 answers · asked by worried person 1 in Physics

The question seems a bit ignorant. I dont mean free land in sense that it was 100 yeas ago when indian land was given away for free.
When you look at google maps, it seems that all of USA is pretty much inhabited or turned into agricultural areas.
If you look at europe , then there is no unhabited land at all unless you wanna build a house somewhere in the Alps.

2007-12-31 01:36:33 · 9 answers · asked by martiini 2 in Geography

mine needs to watch the weather channel

2007-12-31 01:27:33 · 5 answers · asked by lisaw 2 in Weather

Regarding storms, whirlpools, large sea creatures.....

2007-12-31 01:25:29 · 5 answers · asked by ? 4 in Earth Sciences & Geology

2007-12-31 01:25:06 · 12 answers · asked by Anonymous in Earth Sciences & Geology

2007-12-31 01:24:15 · 6 answers · asked by lisaw 2 in Weather

If the moon can make the tides then is it possible to make some sort of device that makes little particles move by the moon's gravity?

This probably sounds conufsing but I am talking about some sort of gravity detector, detecting the small movement of particles(or something bigger) caused by the moon's gravity.

2007-12-31 01:22:46 · 2 answers · asked by worried person 1 in Physics

2007-12-31 01:14:13 · 6 answers · asked by Claudine A 1 in Chemistry

2007-12-31 01:14:12 · 3 answers · asked by SOHAM K 1 in Chemistry

2007-12-31 01:13:26 · 2 answers · asked by Claudine A 1 in Chemistry

2007-12-31 01:02:15 · 2 answers · asked by Kissa Moh 2 in Earth Sciences & Geology

If I put my finger and a 9V battery in a cup of water, what will the result be? Just a shock? Unconsciousness? Death?

I was thinking of trying something like that but don't want to do something like that just for fun if it's dangerous. 9V-testing on the tongue doesn't kill a person, so it shouldn't either on a wet skin, right?

2007-12-31 00:49:37 · 9 answers · asked by XB 3 in Physics

2007-12-31 00:48:00 · 6 answers · asked by jason l 1 in Earth Sciences & Geology

There is a bus with 7 girls,each girl has 7 bags, each bag has 7 big cats,each big cat has 7 small cats(all cats has 4 legs).
How Many legs are there on d bus????

2007-12-31 00:40:45 · 15 answers · asked by Anonymous in Mathematics

2007-12-31 00:28:09 · 17 answers · asked by joycewales 1 in Mathematics

2007-12-31 00:23:15 · 6 answers · asked by LES B 1 in Engineering

2007-12-31 00:07:46 · 5 answers · asked by Anonymous in Chemistry

Jaime and her friend can keyboard 45 words per minute. Six other students in the class can type 30 words per minute. Four students have not yet timed their speed. Find the ratio of students who have timed their keyboarding to those who have not.

.5
2
.7
1.5

2007-12-31 00:07:28 · 3 answers · asked by sunny p 1 in Mathematics

A curve C represents the graph of y=(x^2)/25 x≥0

The points A and B on the curve C have x-coordinates 5 and 10 respectively.
a)Write down the y-coordinates of A and B
b) Find an equation of the tangent to C at A

I can do part a), but i don't get how i can differentiate (x^2)/25?????!!!!!

Thank YOU in advance :D

2007-12-31 00:06:42 · 6 answers · asked by Anonymous in Mathematics

2007-12-31 00:03:22 · 24 answers · asked by Natalie L 1 in Paranormal Phenomena