Science & Mathematics - 30 December 2007

I think (i just think) its using this formula but i'm not sure how to get the answer: (a+b)^3=a^3+b^3+3ab(a+b)

the anwer is supposed to be : l^3+m^3+3l^2m+3lm^2

2007-12-30 23:59:58 · 8 answers · asked by Anonymous in Mathematics

The definition of a circle is the plane figure whose circumference is everywhere equidistanct from its centre and also cirlce is a closed figure.((oxford Dictionary). If you make the circle half and we are calling it as semi circle by drawing an extra diameter to it. Really if we make the circle half we get half arc. The definition of arc is a part of the circumference of a circle. Examble if we break a bangle then we get half arc. My question is why to add diameter and call that thing as semi circle

2007-12-30 23:47:34 · 13 answers · asked by mad 5 in Geography

OK this is the final one. Question is:

What is the greatest prime factor of (4^17) - (2^28)?

Answer is, apparently, 7.
Again there is a VERY long way of working this out but there must be a short cut. There's obviously some relation between 4 and 2 when powered up (?!) but I can't get all the way to the answer.

Multo thanks.

2007-12-30 23:41:23 · 7 answers · asked by Anonymous in Mathematics

Why does it need to grow in water? Do wild paddy or its ancestors grow in swamps originally?

2007-12-30 23:37:55 · 3 answers · asked by espers_cypher 2 in Botany

2007-12-30 23:37:54 · 9 answers · asked by Anonymous in Physics

I have noticed in my fumblings around the world of mathematics some funny things with square roots. For example:

(sqrt of 72) * pi = 6 * (sqrt of 2) * pi

I can see that something is happening here with factors of 72 but can't quite get my brain around what.

Pls advise. Many thanks.

2007-12-30 23:37:19 · 6 answers · asked by Anonymous in Mathematics

What is the advantage over the earlier methods?

2007-12-30 23:36:44 · 5 answers · asked by P.Anbil Prabu 1 in Physics

Whats the best way to divide large numbers?

Basically this is my question:

A new car costs £13500. The dealer gives a discount of £1282.50. What is the percentage discount?

Now the formula to work this out would be:
13500/1282.50 x 100 = %

But im stuck on dividing it. I cannot use a calc for this question. Would i multiply the both numbers again by 100 to remove the decimal, convert them to a fraction and simplfy them, and work on the division using a smaller number?

Thanks guys and girls.

2007-12-30 23:34:57 · 6 answers · asked by James J 1 in Mathematics

this was a fantastic question asked by my chemistry teacher......................please,also give me the reasons for it

2007-12-30 23:33:53 · 12 answers · asked by Eswar s 1 in Chemistry

Ordinary numbers

2007-12-30 23:31:32 · 38 answers · asked by Anonymous in Mathematics

If I have two equally proportioned triangles (same angles, ratio of sides etc), if the area of one triangle is TWICE that of the other, what is the length of the base (S) of the large one in terms of the smaller (s).

I'm presuming triangle shape is immaterial; it's just that they're equivalent and one is 2x the area of the other; and presumably the answering equation relates to any of the sides you'd wish to compare.

The answer is S = (sqrt of 2) x s.

But how do I know this? Pls advise how I could have worked it out. I have no further data (ie about height etc).

Thanks.

2007-12-30 23:26:39 · 5 answers · asked by Anonymous in Mathematics

2007-12-30 23:23:08 · 11 answers · asked by Mr Innocent 2 in Geography

would remain after 30.0 h has elapsed?

2007-12-30 23:22:22 · 3 answers · asked by Anonymous in Mathematics

2007-12-30 23:22:02 · 8 answers · asked by Grateful 1 in Physics

33 64 223
CI Cu Fr
17 29 87

2007-12-30 23:19:56 · 3 answers · asked by Anonymous in Chemistry

2007-12-30 23:18:29 · 2 answers · asked by Ravi S 2 in Zoology

2007-12-30 23:17:49 · 7 answers · asked by Anonymous in Physics

don't you think it's beautiful to can speak in mathematical terms and be understood by everyone? I think that math is the most important universal language...and I wish one day I can study and work in reserarch maybe out of my land (sardinia)...
sorry for my bad bad english...
the question is: do you appreciate the universality of mathematical language?
bye...and happy new year from sardinia!!

2007-12-30 23:17:43 · 7 answers · asked by Sally Brown 3 in Mathematics

Talk about jumping the gun, building habitats on the Moon for people to live in would be better because the technology to build habitats in a hostile alien environment like Mars would need to be tested first, so what do you think, go to Mars first or go to the Moon first?

2007-12-30 22:55:10 · 14 answers · asked by Anonymous in Astronomy & Space

this has to do with laten heat.. I tried using Q= mL
do I just do (16.50)(3.33x10^5 J/kg) and ignore the initial temperature? where 16.50 is the mass and 3.33x10^5 is the heat of fusion?
I got 5.0 x 10^6
thanks.

2007-12-30 22:53:29 · 4 answers · asked by Anonymous in Physics

Hi, I'm wondering if anyone can recommend a book on the law of attraction that is informative but not too heavy??

2007-12-30 22:48:51 · 10 answers · asked by gemma j 1 in Other - Alternative

2007-12-30 22:45:32 · 3 answers · asked by natarajan_rg 1 in Engineering

q= - [(mcT)+(Ccal x T)]

what is the meaning of the negative sign?

2007-12-30 22:40:45 · 2 answers · asked by Anonymous in Chemistry

2007-12-30 22:39:42 · 3 answers · asked by Daniel H 1 in Earth Sciences & Geology

2007-12-30 22:30:20 · 3 answers · asked by Gabriel 3 in Biology

2007-12-30 22:23:40 · 6 answers · asked by L 1 in Engineering

I would for sure because then i would have gone where none of my friends have gone before.

2007-12-30 22:22:24 · 8 answers · asked by Anonymous in Astronomy & Space

If the lack of pressure doesn't split everything apart and the cold temperature doesn't freeze the water... could the water and oil mix?

and if they did, could they then freeze together in the cold temperatures? or would that new mixture protect the water parts from freezing thereby producing a gell type of substance?

2007-12-30 22:21:58 · 4 answers · asked by frankzhere 3 in Astronomy & Space

2007-12-30 22:18:09 · 16 answers · asked by Anonymous in Zoology

Write each expression as a sum and/or difference of logarithms. Express powers as factors.

(1) log_3 (x/9)

(2) log_7 (x^5)

NOTE: log_3 means "log base 3" and log_7 means "log base 7."

Got it?

2007-12-30 22:05:42 · 4 answers · asked by journey 1 in Mathematics