Mathematics

Just changed the names around for some of the forums. This is a kind of guide as to what you should try and put in each: General Mathematics: Anything that doesn't fit into any of the other subforums. Analysis/Calculus: Any analysis problems (e.g. differential equations, questions with convergence/limits/continuity/etc). Modern/Abstract Algebra: Linear Algebra, set theory, equivalence relations, etc. Applied Mathematics: This is the old Stats and Geometry forums, and its use is now for any maths of a more applied nature. Hope you find it easier to choose where to post your stuff now Cheers.

OK, I know a few, like 'i', but I don't know 'e'. Can someone explain it to me> And tell me if there are any other imaginary numbers?

A pretty easy one just for kicks, and it's a fairly standard proof. Prove that [math]e^{i\theta} = \cos(\theta) + i\sin(\theta)[/math] and hence show [math]e^{\pi i} = -1[/math] (for the more adventurous, try showing [math](\cos(\theta) + i \sin(\theta))^n = \cos(n\theta) + i\sin(n\theta)[/math]).

I was looking through a book talking about the history of the number pi and it was talking for a few pages about the search for a way to find a circle and square of equal area. It talked about the Egyptians and their method and went on to the Greek ideas but never exactly explained what the problem is and why there isn't a solution. I ran out of time looking through the book, so maybe I missed this later on, but could someone explain a little about this?

I had to start a little work out of the old calculus book today. The teacher's want to make sure we understand how to calculate the slope of a line when given two points before we get into the really tough stuff like the slope of a curve and logarithms this fall. (I know I might not be the best at math, but come on). Ths is a question I came upon in the book that I just couldn't find a way around. Incidently, the only reason I saw it was because the teacher told us to skip over that section. So I naturaly tried some of the problems. One of them has me a little stumped though. It came with a diagram, but since I don't know how to paste pictures on here, I'll just des…

Could someone please tell me how to calculate pi in the windows program excel please? If you could post the solution under this thread, or just email it, I would be very grateful. THANKS!

Can someone explain these to me in the simplest way possible? Also the Absolute Infinite.

Let f(n) denote the maximum number of right triangles determined by n coplanar points. Prove f(n)/(n^2) --> infinity as n-->infinity and f(n)/(n^3) --> 0 as n-->infinity.

Just likes to say thanks to you lot for answering my dumb (and sometimes intelligant) questions on the maths forums over the last few months. Thanks to you lot I may just get the B I need to get into Bristol uni (to do Biochemistry, not maths thankgod).

hi anyone knows program for plotting domains of complex variable? such as: 1<|f(z)|<=3 or |arg(z)|<(Pi/4) or even something like this one: f(z)=z^3, |z|<=2, Im(z)>=0 thanks

won't be too many more question, got my last maths exam monday but you help would be much appreciated. Solve for [math]0 \leq x <360[/math] [math]2cos(x + 50)^o = sin(x + 40)^o[/math] and [math]2cosx+sinx = 5[/math]

Please use the attachment. Find the shaded area of the triangle. i've made some changes and i think the diagram cann't be any more clear than this. attachment.doc

Problem Solved...

Hi, me and my mate were talking about uni and stuff. he does computer science at imperial. and this came up. its the famous eight queen problem "All you have to do is put eight queens on a chess board so that none of them are attacking each other." sounds easy rite. but believe me, i can manage only 7. apparently he had to write a program to find a solution to this problem. and yes there are solutions. So now, I dont want anyone to cheat or look it up on the web. I would just like to know how a mathematician would go about solving this. I was thinking about using matrices. a 8by8 matrice. but then i dont know what to do with it. anyway if anyone can find a so…

What the hell is this equation? Aproaching zero, y became fractalized (?). It goes up and down in incredible way.

exactly as the topic says... any ideas plz?

Don't know whether you've all noticed, but there's an encyclopedia module included in this version of vbPortal (which is the portal system we use for vBulletin). I have a few ideas to create a mathematical encyclopedia section (there's already a science encyclopedia with 1 entry in it ) to link to various key ideas (e.g. famous theorems, matrix operations, definitions of important functions, etc), a bit like MathWorld but on a smaller scale. This way, if someone has a question in the future that we've already answered using a theorem, we don't have to go and state the theorem every time, just point a link to it. Any thoughts/suggestions?

This is a quick and dirty guide to using mimeTeX on the forums. The aim is to make it a little bit easier for you all to post proper mathematics, and not have to mess around with bracketing and things like that. The first thing to note, is that when you use the math tag to encompass an equation, there cannot be any spaces in the text. Otherwise, your equation will not render properly. Instead, you must use a tilde (~). The second thing is, because mimeTeX is essentially a front-end for TeX, this means that syntaxically, the language is quite complex. This is for a good reason; it is very hard to properly typeset mathematics, and a great amount of detail is needed …

y = psinx + qcosx passes through the points (0,3) and (pi/4,0). Find the values of p and q. Using formula on the coordinates i've got y = 3 + 12x/pi so psinx + qcosx = 3 + 12x/pi but then where? only 2 identities i need for this course is sinx/cosx = tanx and (sinx)^2 + (cosx)^2 = 1 but i cant see how i can use these

I came to thinking whether there is such thing as randomness in math. So far, from my studies of math I can only see strictly defined patterns with definite outcomes. For example, take the pseudo random number generation in computer science. Those numbers are nothing but the outcome of many factors taken into the equation. So, the question is if math is supposed to explain (or come from) the nature, wouldn't this contradict the thermodynamics law of tendency to strive to randomness? Or, if there is nothing random about math, is it fair to say that there is no such thing as occurance by a pure chance in nature?

Take a four digit positive number A, reverse the digits to make number B show that A^2 - B^2 is always divisible by 99 example: A=3785 B=5873 first question in my analysis exam today , dont know why.

Everything has a pattern e.g. if a coin is flipped there is an equal chance of tails and heads if the coin is fair. If coin flipped 10 times you would expect 5 heads and 5 tails, in reality, randomness stops this from happening. However, if the coin is flipped a million times then there will be a 50:50 split between heads and tails. Does this mean in theory that you could travel in time as there must be a pattern to everything? And as you got further away from present it would be more accuracy as randomness would have less of an effect? THIS IS ONLY IN THEORY!! Are there any problems, in theory, to this?

Thanks dave for the last piece of information. I find myself stuck on a question about triangles. What is the side length of an equilateral triangle if the area is 1732 cm squared. What is the equation? I'm missing something? Thanks in advance

go to http://hyperphysics.phy-astr.gsu.edu/hbase/alg2.html#ap scroll down to the part on algebra practice equations. x = (b(e-c))/(a-bd) so a can't = bd or the equation becomes undefined. put x + 0 = x + 0 and you get NaN. what's NaN? Does that mean all real numbers? put x + 1 = x + 0 and you get -Infinity... I don't get it. I thought it was null set. put x + 0 = x + 1 and you get Infinity... I don't get that either. I thought it was null set.

i just signed up; i'm a 4th-yr student @ U of Victoria, BC, canada & I just want to talk math with people