Mathematics

Hi, I just signed up for this forum, so hi everyone! I also have a quick question though, anyone know where I can find the multiple choice answers (not the free response solutions) to old AP exams? specifically 98, 88, 92 and 93? Actually, any of em would be great, I'm eventually going to have to do all of them, thanks a bunch!!

Anyway. I am a Maths Student at University of Nottingham. Just about to finish my first year. Have exams in may/june. Ok then. introductions over, ill give u a started question: Find all integer solutions for ab=ba given that 0<a<b. Its a really nice question I found in a book. It has a nice solution as well. ooh dont bother with that question. i see that its been asked in other sub forums HEHE anyway later

Was just wondering whether anyone had any ideas as to how to get more people posting on these mathematics forums more frequently. We definately don't have the largest userbase in the world, but I think it's a shame to just let the forums go to waste. The competition idea was a good idea (I think), but I didn't get too many replies from it. I think I may have made the problems too hard, and this put a lot of people off. If anyone has any other ideas, I'd love to hear them, because I quite enjoy reading the posts on the maths forums and it'd be great to get some more people on them Cheers.

3 Guys walk into a hotel The person at the counter says it's 30$ for a room for all 3 of them The 3 guys pay 10$ each to split up the cost evenly Later on the night the manager knocks on there door and says he made a mistake and it was only 25$ for the room. He gives them back 5$ Each of the guys take 1$ and give the remaining 2$ to the bell boy. So, each person payed 9$ total 9*3 = 27$ + the 2$ for the bell boy = 29$ What happened to the remaining dollar?

I basically want to know the general method of 'proof by condraction' and an explanation behind it, an example I've been given is: Complete the following proof by contradiction to show that (5)^(1/2) is irrational. Assuming that (5)^(1/2) is rational, let (5)^(1/2) = a/b where a and b are integers that have no common factors Then 5b^2 = a^2 -> 5 is the factor of a^2

I'm trying to write a program in C++ that does square roots. does anyone know the algorithm for a square root using division, multiplication, addition, subtraction etc.

Sorry, it has been so long since i took math. If you have a value (lets say 8000) decreasing by 13% every hour (13% of its actual value not the original value). What would be the formula to find out the current value after 5 hours. Its like bonds. You invest money and it keeps increasing in accordance with the current value. thanks in advance.

Sorry for the wait (I'm sure you all missed it really), but I decided to do another question for this week. It's quite good fun, but you'll definately need to think about it. Enjoy! mathsprobs3.pdf

Forum Rules Also please note that the posts from the old Fractal forum have now been moved to Modern/Abstract Algebra. [*]Please refrain from posting non-mathematical related information onto any mathematical forum. The General Discussions forum should be used for this purpose. [*]Specifically, this forum (i.e. General Mathematics) should only be used for threads which do not fit into any other category of mathematics forum. Any posts of this nature will be moved to the appropriate forum. [*]Where possible, please use correct mathematical notation, and, in particular, use of the correct tags for superscript and subscript as well as proper bracketing of formulae…

here`s one for the "maths" folks. yet again I`ve won on the Grand National (horse racing). I`ve won ever single year for the last 22 years without fail. I bet on 3 horses only and the average amount of horses in the race is about 40. the amounts I bet are only small as I play for fun only and it`s only once a year. I`ve never come back with less that I`ve bet in 22 years. I bet Each way, meaning that my bet will take into account 1`st, 2`nd, 3`rd and 4`th placements. what are the probabilities of this being acheived?

Where can I found the Helmholtz theorem which says that I can always decompose a vector in 2 parts?

4sinxcosx-2sinx-2cosx+1 = 0 Need all solutions in the range 0 < x <=360 Just a clue would be nice, i'm totally flummaxed. question 22 of excercise 2c in the edexcel p1 book if you have it.

there`s a quid riding on this! make a 3 by 3 grid a bit like a Xand O`s game. inthem are to be Whole numbers that along the lines must add up to 55, the same down the colums and on the diagonal, a bit like those magic squares. so far I can do 54. they MUST be whole numbers, but negative numbers or Zero are allowed too and you may use the same numbers twice if you want. HELP!!!!!

What's ma error mean? What's Syn Error mean? Are there any other errors?

If you had b^(m/n), is it a) nthroot of (b to the mth) b) (nthroot of b) to the mth c) either d) both

I don't get this. Do you take the root first? Or take the power first? (-4)^(2/10). Do you take the tenthroot first? If so, you would run into imaginary numbers right? But if you square it first, then you don't have imaginary numbers? Do you always simplify the fraction? So do you turn it into (-4)^(1/5)? Each yields a different answer. One's imaginary, one's positive, one's negative.

Thought I'd post this for your enjoyment. I thought it was quite nice. Enjoy. dblint.pdf

1. Which triangle has the greatest area? (see the attached image) 2. Arrange the numbers 1 to 9, using each one only once, placing only one number in each cell so that the totals in both directions are the same.(see the attached image) 3. A man and his wife each weigh 50kg. They have two children each weighing 25kg. The whole family to have cross a river in a rowing-boat which can only carry a maximum of 50kg. Every member of the family can row. How can they manage it? 4. Which is bigger and by how much- the sum of all the odd numbers or the sum of all the even numbers from 1 to 100? 5. I multiply a number by 4 and add 9. The result is the same as when I m…

I forgot the formula on how to convert regular polygons into circles. What I mean by this is by plugging the length of an apothem or a side into a formula, and you yield 3.14159... The formula has to have the number of sides too. It shows how if the number of sides increase, the polygon becomes a circle. I believe the formula includes sine if you plug in the side and includes cosine and tangent if you plug in the apothem.

Since the forum really does run the risk of going completely sour if someone doesn't post something in it, I thought I'd try to liven it up a bit. I don't know whether anyone who reads these forums has ever written a maths thesis/paper, but I think it'd be quite interesting to find out whether anyone has any particular areas of mathematics that they're fascinated/interested in, or whether you've ever written any papers/theses/short proofs/whatever on anything. Personally, I'm quite interested in the convergence of infinite series and finding their limits (mainly from all of the work we've been doing on it in Analysis this term). Hope we get some more people replyi…

1. Taking an exact number of strides I can walk 9.49 metres. What is the length of my stride? 2. Make a copy of a triangle like that shown with four circles along each edge. Use the numbers 1 to 9. Put one number in each circle so that the four numbers along each edge add up to the same total. Find two different ways of doing this. <IMG height=238 src="http://www.rashidschoolforboys.sch.ae/pages/Maths%20Website2/photots%20for%20maths/trianlge.JPG" width=266> 3.If you multiply together all of the factors of 100, how many zeros will there be on the end of the answer? 4.In this multiplication problem: ?? x ? = ??? all of the digits have been replaced by…

This week, there's three questions that are all a bit easier than last week's really. This time they're included in a PDF file, so enjoy I'll post the answers in exactly a week's time, and probably a couple of hints too. mathsprobs2.pdf