Mathematics

Show that: if the sum of the digits of a natural number N is divisible by 3 then 3 | N.

Hey all, I was wondering the other day, if you rotate the plot of [math]y=x^2[/math] 90° CW, you get [math]y^2=x[/math]. What happens when you do the same with [math]sin(x)[/math]? In other words, which function looks like this: Cheers, Gabe

What is the total sum of all numbers? zero?

Hi everyone, I have some homework to do and ive been asked the following question....... a) Construct an internally and externally calibrated calibration graph. This must be done using Excel and also using graph paper and a pencil (i.e. four graphs are required). my question is what is the difference between an internal and external calibration graph? I have the data. Any help will be much appreciated

we teach in türkiye-anatolia ,Natural Numbers to start at 1 and not to include zero.. but, I could never understand how one could not say that 0 were a natural number if zero(0) is a Natural Number,why? someone said:It depends on the frame of reference you use. right?

Hi. What would be the vertical motion amplitude at 5 metres below surface for a seawave of 0,5m amplitude (1 metre peak to trough) at surface? There is some formulas at wiki but unsure how to translate them into what I want to know

x^4 +y^4+z^4 =4xyz-1 denkleminin bütün gerçel çözümlerini bulunuz x^4 +y^4+z^4 =4xyz-1 Find all real solutions of the equation

Hi My teacher asked me to program this thanks to Matlab, but I am not able to understand anything: "Indeed, we first compute the short-time magnitude spectrum and phase spectrum of the segment in a neighborhood (32 ms) of the sample Note that the spectra are obtained through first multiplying the segment by a 256-point Hamming window followed by performing fast Fourier transform (FFT) analysis. Moreover, such operations are carried out for each sample. Second, we compute the short-time magnitude spectra of four neighboring segments which overlap with the original segment by 12 or 24 ms (i.e., two of the neighboring segments are obtained by shifting the analysis…

Hey guys, I talked with a guy who studies mathematics and he told me that his friends from collage found their "limits" (mostly in third grade) and now the don't have a clue what's going on, and just learn mechanically like medival scholars did. He also told me that only some chosen ones still understand it. Does anyone you know of feel a similar effect? And now something completly diffrent, will you press (softly, of course) on your child to do math?

Hey all, I'm curious as to how to calculate the surface/volume of a shape I though of the other day. Since I don't know if what it's called (heck, I don't even know if it exists) and I'm not even close to being good enough with Photoshop to make a picture, I'll have to describe it, which may prove a little tricky. So, here we go. It's three dimensional. Imagine you have a circle with center [math]S_1[/math] of radius [math]r_1[/math] in space. Now imagine on either side of it, an n-sided convex regular polygon with a center [math]S_2[/math] and diameter (that is, the distance between the center and the place where two edges meet) [math]r_2[/math]. The distance bet…

Mathematics is certainly a science in the broad sense of "systematic and formulated knowledge", but most people use "science" to refer only to the natural sciences. Since mathematics provides the language in which the natural sciences aspire to describe and analyse the universe, there is a natural link between mathematics and the natural sciences. Indeed schools, universities, and government agencies usually lump them together. (1) On the other hand, most mathematicians do not consider themselves to be scientists and vice versa. So is mathematics a natural science? (2) The natural sciences investigate the physical universe but mathematics does not, so mathematics is not r…

Let me first (loosely) define both synthetic and analytic geometry. Synthetic geometry- deductive system based on postulates. The geometric objects are endowed with geometric properties from the axioms. This is includes the "high school" geometry of drawing lines and measuring angles etc. and from there making deductive statements. A geometry can be defined as a set plus a symmetric, reflexive relation. (Does it really need to be a set?) Analytic geometry-represent geometric objects using local coordinates. This makes much use of algebra (and in the differential case, calculus). I will also include algebraic geometry here (so sheaves, affine varieties etc …

Why 2 multiply 2 is equal 4?proof?

http://www.dimensions-math.org/Dim_regarder_E.htm I recently found this amazing recource. The whole of the first series is on one subject but I like that in that it starts simply and dosn't move to quickly. It builds up to verry complex stuff.

There was some discussion as to whether maths could be considered art. I was sent home from work today, due to a rather nasty infection, so I decided to plot some simple functions through mathcad, that shows you can manipulate an equation to obtain a desired shape. For anyone who uses mathcad, I've supplied the functions at the top of the pics. Not particularly special, but I hope it illustrates you can be creative with maths if you wish...I've added pretentious names, to make the images more arty Hmm, having problems uploading pics... Right...Dark Knight, and Valley of the Icey Math People. Note the functions are very simple, but plotted on a surface.

I've tried distributing etc but cannot get the correct answer of 60.1N My book doesn't give the steps. Tsin37 + (1.33T)(sin53) - 100N =0 I never know what to do with the (1.33T)(sin53) Any assistance would really be appreciated.

Correct me if I'm wrong, but is the difference between Euclidean geometry and non-Euclidean is that the latter includes the former but simply added the idea of doing measurements along the curved surfaces of multi-dimensional spheres and objects?

Hey guys. I'm really interested in learning discrete mathematics and logic. What math should I already know before buying a discrete math textbook?

Hey there all, this might be a pretty stupid question, but is there a method that allows one to extract the function from a graph? I know that one graph can represent many different functions, but if I didn't care which one, as long as that function would produce the same graph when plotted. Also, I don't mean functions that look like [math]f(x)=\begin{cases} \mbox{something} & \mbox{if } \mbox{something} \\ \mbox{something else} & \mbox{if } \mbox{something else} \\ \mbox{still something else} & \mbox{if } \mbox{still something else} \\ \mbox{\vdots}&\mbox{\vdots} \end{cases} [/math] ..and have a separate condition for every point. I know th…

Apparently mg + mv^2/r = mg(1 + v^2/rg) but does anyone know what is the name of the process?

Hey all, well, the title speaks for itself. Given a cube, what is the angle between the diagonals of two neighboring squares? Here's an illustration, just in case: It looks a little strange since it's a 2D picture, but I think you get the picture. Literally. My gut tells me it's either 45° or 60°, but...well, that's just my gut. the title almost speaks for itself. Given a cuboid, where [math]a \neq b \neq c[/math], how can I calculate the angle between the diagonals of two neighboring rectangles? Cheers, Gabe

Is it possible to create a logarithmic algorithm of prime numbers and a sequence of factors to produce a table in Exel.

Google docs gives the option to draw an orginisation diagram, it shows hyrachy in an orginisation. me parent son1 me son2 me son3 me Drawing this gives you a box at the top entitled parent with a line going down to me and then branching out to 3 sons. Moving on to another expample. 2n n 0 0 2 1 4 2 6 3 The values in the top row are lables, the second column is increased by 1 each row. The first column is double the second column. If we continue this chart up to n=40 and draw it according to the rules this is the result. http://img253.imageshack.us/img253/7651/image1kq7.png This allows you to see th…

Is it possible for something to have a negative number of dimensions? Or is that just meaningless? How about imaginary dimensions? The reason I ask is that there seems to be something missing in the table of simplex elements to make a complete Pascal's triangle.

Hey all, as some may know, I've been attempting to learn calculus lately, and despite the fact I though I had already mastered the part of the tutorial I was reading, I did encounter a slight problem for which I cannot find a logical explanation. Let us have a [math]f(t)=2t + 1, t\in N[/math]. Its graph would then be a line going starting at [math]A=[0, 1][/math] and going through [math]B=[1, 3][/math]. If we subtract two from the output, we will get [math]f(t)-2=2t-1[/math]. The graph will be a line starting at [math]A=[0, -1][/math] and continue on through [math]B=[\frac{1}{2},0][/math]. In other words, the graph will be moved down by two. It's minus, so it's do…