Mathematics

This is concerning the maths problem where you are in a gameshow and three doors are available behind 2 there are goats but one is a car. You choose one but do not open it. The host opens one of the two that you did not choose and shows a goat. Should you open the door you chose or change your mind with the remaining one door? Well you should change door Please somebody explain the maths of this (No there is not a 1 in 2 chance on getting the car in the remaining 2 doors)

can anyone educate me on this topic, as i would like to integrate it into my lab report results, also thats what the lecturer suggests. i have 3 sets of results with 4 readings each against time with 1.5s interval from 0 upto 6s. thanks alot

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

[math]U = f(x,y)[/math] Can someone explain to me how [math]\frac{dy}{dx}=-\frac{\partial{U}/\partial{x}}{\partial{U}/\partial{y}}[/math]? _______________ http://members.fortunecity.com/ku20/oldindex.html

Spent some time finding the thread that asked how to find 20x + 10x^2 = 0 So, moderators, please help. Sorry. Ok, you can solve graphically although i know the answer might not be accurate. By trial and error, i got an answer where x=0.03... something. I guess you can't solve by log as you can't log a negative 20x. the answer should be from between y=-20x and y=10x^2 I think only by using a special software to graphically draw out the graph and read from it. Hope it might help. :x

Dumb question: Is the infinite dimensional vector space (with finite number of non-zero components of course) over a countable field countable? I tried to look it up, but couldn't find anything. I don't need a proof, just maybe a little plausible explanation if possible.

How do they work? I heard that equations based on the seed value are used. If so, do you have any examples of them?

I was just curious, since I have no idea what the most advanced math stuff is these days (I've never really understood anything higher than a calculus 1), I was wondering what the newest stuff to math is. What kinds of things are they still working on? What are some of the newest fields they've discover/invented? What's actualy left to work on? If I want to be a mathemetician, can I look forward to have anything to work on?

Hello Teachers! Teacher's day in the year 2004 fell on Sunday.On what day will the teacher's day in the year 2005 fall on ? How to solve this problem? I am in 4th grade? Thanks.

Anyone has read "elements" before?

Ok, I've got this integral, having slight problems solving it: Int ( [coth(x/2)-1]sin(ax) dx ) from zero to infinity. Now, I've expanded coth(x/2) = (e^(x/2)+e^(-x/2))/(e^(x/2)-e^(-x/2)) = (1+e^(-x))/(1-e^(-x)) So I get the integral Int( 2e^(-x)/(1-e^(-x))sin(ax) dx). I've thought that this may be siplified using the sum sum_n ( z^n ) = 1/(1-z) when n goes from zero to infinity, thus I get 2*int( e^(-x)e^(-nx)sin(ax) dx) Any tips on what to do next? i know the solution of the integral to be pi*coth(pi*a)-1/a, but can't figure out how to get there.

Why can't the square of radical negitive one equal to one? Unless of course, it does equal both one and negitive one, making it similar to the mathamatical avatar of the light, since light is both wave and photon...

Hello, I've been using Mathematica recently, and I was curious to how you would find the value of two variables to plug into an equation.. it's a simple problem, I just don't know how to type the formula into the program. Example below: Provide an ordered pair (m,n) of numbers that satisfy the following equation: 5m-n=9 Thanks!

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?

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.

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.

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?

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

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?