Mathematics

I'm trying to figure out the energy consumption per person per day in the US, but I think I'm messing my dimensional analsys up somewhere. Whoever figure it out first gets a cookie! In 2001 the USA used 96275 trillion BTUs of energy that year. This comes to 3.22 trillion watts expended annually or 8.82 billion watts each day . Now there are about 295 million people in the US, so this comes to about 30 watts per person per day ..... wait this can't be right.... Am I doing this wrong, or is my data bad?

Hello Teachers! Largest 3 digit number divisible by 25. IS there any simplest method to solve it? Thanks.

I have to do a presentation on a math article for a senior topics class in a couple weeks and i was wondering if anyone had a good article on hyperbolic space that has a proof in it that is fairly graspable. Or if anyone has any interesting article so long as it has a proof in it and is not super long. Thanks guys Nathan

Anyone has read "elements" before?

Sir, The difference of two number is always 1.equal to one number or less than both the number. IS (1) correct? Could you please explain it to me? Thanks.

Sir, How many chord can pass through the center of a circlr? Thanks.

Hallo Teachers! How many line symmetry in the figure: X thanks.

Hello Teachers! How to add number from 21+22+............+30? IS there any simolest method? Thanks.

Im having difficulty cancelling down the following; (n+(W-1) * n+(Gw*(L-1))) – (n* n+(GW *(L-1))+(W-1)) anybody got any ideas?

consider the set : A = {(x,y) ε (N × N) | x <y , 2x^2 - 5xy + 2y^2 - x - y - 1 = 11} The problem is to determine number of A's members. I have found x=2, y=6 as an answer. But I haven't been able to prove it's uniqueness and I'm not even sure about that. Because my solution is not complete, I don't bring it here. Can anyone help me on this?

mathematicians here might find it amusing , taken from bash.org "Impure Mathematics ------ ----------- To prove once and for all that math can be fun, we present: Wherein it is related how that paragon of womanly virtue, young Polly Nomial (our heroine) is accosted by that notorious villain Curly Pi, and factored (oh horror!!!) Once upon a time (1/t) pretty little Polly Nomial was strolling across a field of vectors when she came to the boundary of a singularly large matrix. Now Polly was convergent, and her mother had made it an absolute condition that she must never enter such an array without her brackets on. Polly, however, who had changed her…

If ex - fy= gx + hy find ratio of x to y Answer is highly appreciated.

How do you solve problems like f=ma? For each variable, you put in a different number, but they are described in different units, like pounds, or pounds per square inch. How does it work?

Ok, so on this other forum I go to, one of the users asked for help explaining exponents to her kid and how the work for his homework. Most of it I could cover, but one thing I couldn't. We all know negative exponents, and simple stuff like 1/(x^-2) = x^2, and it's easy enough to simply state the rule, but my question is *why* is that rule the way it is? I mean, what's the derivation behind it? I hate to say "it just is that way, kid", but it's been a hell of a long time since I took Algebra, and I don't remember the reasoning for it. So, basically, what I'm after is a logical explanation for the way negative exponents work, that I can present in a form a kid t…

I need mathematicians to tell me whether the quotation below makes any sense mathematics-wise; and please explain to me in man-in-the street-language what the author is saying. Thanks for any help from anyone skilled in mathematics. yrreg

Find a 2x2 matrix A and a vector v in R2 such that the transforma- tion x --> Ax + v maps the triangle with vertices (1, 1); (2, -1); (3, 4) into the triangle with vertices (0, 0); (1, 0); (0, 1). How many different pairs (A, v) will do the job?

Mobile phone operator zim" in my country is saying it has more than four million clients. If a phone number is 9 digits long and always starts with a 6... How is this possible?

Hello, can someoneu help me with Integration of function f(x) = sqrt(ln(x)) or (ln(x))^(1/2) ...

Just watching on the way home today, I was wondering there must be some underlying mathematics to traffic patterns, Probability of Jams etc?

Hi! Can someone please explain to me how to integrate: ln4x+cos4x+3. I don't know how to integrate ln4x. Please show me the steps, and explain what integration by part means and how to use it. I have tried to look on it but I am still not clear. Thanks

Hello, Can anyone please provide website(s) for challenging problems that are related to gr.12 curriculum. Thanks

y=(-x^2+1)^1/2 How do i integrate this guy from 0 to 1? since the x^2 has a negative constant, would you need to integrate i? like this [ix^3/3+x] OneStone

Is there a particular solution to this equation: N=p^2/q^2, where N is any prime number and p and q are two intergers.

Hi everybody! As it seems to me I have found quite simple way to prove the "Four Colour Theorem". I am not a mathematician so I can't bear any illusions about my paper but I hope you can find it containing something interesting. You can see it at http://www.geocities.com/itutber. Your comment would be very welcomed Best wishes Ilia Tutberidze

ax^2+b^x+c is the standard function of a quadratic. If i know that a quadratic with this format passes though points A(-3,-2) and B(2,3). How would i go about working out a, b and c? This's got me stumped. Thanks