Multiplication Definition and 484 Threads

Homework Statement Well, basically my issue isn't exactly with how to multiply matrices. I know how to do that, my issue is the way my lecturer shows how to find the size of the new matrix, this is all that he shows: I mean how is he getting AX to be a 3x1 matrix? Homework EquationsThe...

I would love someone to verify the answer for equation 8 in this paper (bottom of page 263) http://onlinelibrary.wiley.com/doi/10.1046/j.1365-2028.2002.00368.x/epdf For the sake of clarity here is the equation is LaTeX which you can render at the following link \frac{QC + Q\lambda \sigma -...

Homework Statement x(cnxn-1) 3. The Attempt at a Solution I know that the answer is cnxn I'm not sure why though. My thinking is that we have cnxn-1 and we multiply that by x. x times x is x2 so I'm expecting a 2 to interact with the n-1 in the exponents. I'm just not sure how n-1 interacts...

Hello, I have been poring over this problem for days, and I would really appreciate some help. I'm not sure if it's an algebra problem exactly. It's from my physiology class. The professor said it's simple cross multiplication, and I asked him to explain it again, but I didn't understand his...

I've heard it said that the commutation relations of the generators of a Lie algebra determine the multiplication laws of the Lie group elements. I would like to prove this statement for ##SO(3)##. I know that the commutation relations are ##[J_{i},J_{j}]=i\epsilon_{ijk}J_{k}##. Can you...

Is there some kind of intuitive way to understand the physical meaning when mathematical operations are applied to equations in physics? What I mean is that, say we start with a 'starting point' equation, in this example Ficks law of diffusion (wikipedia:): J = -D \frac{\delta \phi}{\delta x}...

Create a program in C++ that makes a multiplication table. Ask the user how many numbers should be in the table. Requirements Store all of the data in a 2-dimensional vector of ints. Allow the program to run repeatedly until the user is finished. Do not allow inputs outside the range of 1-9...

Homework Statement Let ##G=GL_n(F)## for ##F## a field, and define an equivalance relation by ##A\sim B## iff ##A## and ##B## are conjugate, that is, iff ##A=PBP^{-1}## for some ##P\in GL_n(F)##. Does ##\sim## respect multiplication?Homework Equations The equivalency respects multiplication...

Homework Statement A 1 200-N uniform boom at 65 degrees to the vertical is supported by a cable at an angle of 25 degrees to the horizontal . The boom is pivoted at the bottom, and an object of weight = 2 000 N hangs from its top. Find the tension in the support cable Homework EquationsThe...

Homework Statement Selecting Two Balls. Suppose that two balls are to be selected at random, without replacement, from a box containing r red balls and b blue balls. We shall determine the probability p that the first ball will be red and the second ball will be blue I am confusing Pr(A|B) and...

Work = Force X Distance. ? = Distance X Force How do you make sense of the second equation?

Hi i am trying to understand this thoroughly Basically i am trying to understand vector multiplication, i don't know if it is the cross product or the dot product i am thinking of Okay so here is the question and what is confusing me in the answer So if we have two vectors and we multiply...

Hello! (Wave) For polynomial multiplication, if $A(x)$ and $B(x)$ are polynomials of degree-bound $n$, we say that their product $C(x)$ is a polynomial of degree-bound $2n-1$ such that $C(x)=A(x)B(x)$ for all $x$ in the underlying field. A way to express the product $C(x)$ is $$C(x)=...

Homework Statement I am reading Rudin's Principles of Mathematical Analysis (3rd edition) and am working through the construction of ##\mathbb{R}##. In step 6 of his construction, we must first verify that the field properties of multiplication hold for how he defines multiplication for the...

I've been going over the cross sections on Sigma, and I'm a little confused as to why beryllium is the most talked about neutron multiplier I've come across. I mean, it does have a few things going for it: multiplication down to lower energy levels than most multipliers, and a very low (n...

In Chapter 7 of John M. Lee's book on topological manifolds, we find the following text on composable paths and the multiplication of path classes, [f] ... ... Lee, writes the following:In the above text, Lee defines composable paths and then defines path multiplication of path classes (not...

Let A= (sin(x) * sin(100x)) + sin(100x).; modulation index is 1; Let B= (sin(x) + sin (100x)); Both of these waves have same frequency and both are amplitude modulated. When passed through an envelope detector, both will give message signal. And B have an advantage of not having any sideband...

Homework Statement That is, use three specific vectors in 3-space to show that...

Hi guys, I am taking this class in lie groups but the professor never introduced the concept of quaternion and he asked about it. I saw from google the properties of multiplications of j and I made the multiplication according to (B + jC)(u + jv) = Bu + Bjv + jCu + j^2Cv = Bu - Cv + j(Cu + Bv)...

Hello! (Wave) For each pair of natural numbers $m \in \omega, n \in \omega$ we define the multiplication between $m,n$ (as a function $\cdot: \omega \times \omega \to \omega $) like that: $$m \cdot 0=0$$ $$m \cdot n'=m \cdot n+m$$ I want to show that for each $m \in \omega, n \in \omega, k...

If Anna has 0 coins and Bertus has 0 coins aswell. Can you say that Anna has twice as much coins as Bertus? Because 2*0=0. But couldn`t you also say that Anna has four times more coins than Bertus, but simultaneously Bertus has 5 times more coins than Anna? Making it a paradox?

(I have posted this in this section, rather than homework, because I hope to improve my general understanding of methods of finding limits through these problems.) 1: \lim_{x\rightarrow0} (\frac{cosec(x)}{x^3} - \frac{sinh(x)}{x^5}) I don't really know what to do with this one. I tried...

I was tutoring a student and I came across the following question. I feel like I'm missing something obvious, but it seems like there are too many variables for an answer to be determined. The attached picture contains all of the question details.

Hey! :o I am looking at the divide-and-conquer technique for the multiplication of two $n-$bit numbers.First of all, why does the traditional method of the multiplication of two $n-$bit numbers require $O(n^2)$ bit operations?? (Wondering) The divide-and-conquer approach is the following: Let...

Homework Statement Let n,m be natural numbers. Then n x m = m x n. Prove this. Homework Equations In order to prove this i am asked to prove 2 Lemma that will be useful. In my solution i will (attempt to) prove these first.Definition of multiplication; for all m in N 0 x m = 0, (n++) x m :=...

Homework Statement [/B] This is a seemingly simple problem. All I have to do is multiply two matrices: [ 1 0 ] [ 0 1 ] (A) and [ 2 ] [ 3 ] (B) The Attempt at a Solution [/B] Because the matrix A has the same number of columns as matrix B has rows, and because matrix A is an identity matrix...

Why do many multiplication tables for grade school students go up to 12x12, when a table up to 9x9 is sufficient for any multiplication problem?

Hi, I know that area of rectangle is length x breadth. I tried to find proof of area of rectangle but I found that the proof was solved by taking formula of area of square into consideration. But what I don't understand is why area of rectangle should be length times breadth, or side times side...

Homework Statement The number of bacteria in a culture is given by the formula n(t) = 700e0.65t, where t is measured in hours. What is the initial population n0 of the culture (at t = 0)? n0 = Approximately how many bacteria, N, will the culture contain after 5 hours? N = The Attempt at a...

I am trying to do an exercise where I am showing that the set of all elements of $\Bbb{Z}_n$ that are coprime with n form a group under modular addition. So far I have shown associativity, identity, and closure, but I'm having trouble showing the existence of an inverse. I know I can't use...

I'm now a 19 years old undergraduate physics student. I've a reasonable proficiency with calculus (well, no really...) but if you ask me 6*7 (unlike my mother and many other older people I know) I'll take awhile until I come up with an answer (I'll ask myself 6*5 and then add 12 to that result)...

Homework Statement For the vectors in a Triangle, with a = 16, b = 12, and c = 20 what are (a) the magnitude and (b) the direction of A x B (c) the magnitude and (d) the direction of A x C (e) the magnitude and (f) the direction B x C this is Vector Multiplication. Homework Equations...

Hi, I am studying linear algebra from Golub G.H., Van Loan C.F.- Matrix Computations 3rd edition. This book is somewhat old now, but I find it rather comprehensive. I want to study all chapters and answer all problems appear at the end of each section. Here is the first problem from the first...

Homework Statement Still having a little trouble so here's the problem. (ex + ez) x (3ey - 4ez) The Attempt at a Solution (ex * ez) + (ex * (-4ez)) + (ez * 3ey) + ( ez * (-4ez) now, these are all orthogonal to each other, so, for example, if I have ex * ey then I should end up...

Hi, What does N*m mean? What does N/m mean? What kWh mean? What kW/h mean? What does F=m*a mean? I read maybe all articles on web about concepts of multiplication,units,differences.But respondents only starts with some question(You know,what is dividing,but you do not know what...

Dear All, I am a starter to machine learning and i am currently confused about the following problem: what is the result of P(X|Y)P(Y|Z)? In my book, it is written to be P(X|Z). But I don't think it is correct since P(X|Z)= P(X|Y,Z)P(Y|Z) But clearly P(X|Y)=/= P(X|Y,Z) Assuming...

I am learning Javascript and have made a multiplication table generating program. But it's about 1000x slower than C#. Is there any problem with this code? I used the same code as C#, just the syntax is different. Here is the code: <html> <head lang="en"> <meta charset="UTF-8">...

Is this statement true? \bf{Re}\{z_1 \times z_2\} = 0 \,\, and \,\, z_2 \ne 0 \Rightarrow z_1 = 0 \,\,\, where \, z_1; z_2 \in \rm{C} Thanks.

I am working with polytopes that are defined by half-planes in \Re^N. So they are defined by a number of inequalities (half plane representation), but can also be represented by the intersection points of these half planes (vertex representation). Computing the vertices is expensive, so I...

Hi, in Matlab I encounter with two new operations for me which are array multiplication and array division. I want to learn that do they have physical applications in real world physics problems or are they be related with banking and accounting.

This is my code: double of = 0; double from = 0; double to = 0; double ans = 0; private void button1_Click(object sender, EventArgs e) { Table.Items.Clear(); if (double.TryParse(Of.Text, out of) == true &&...

I've never quite understood is how formula can involve division and multiplication while dealing with abstract concepts. Such as, ohm's law V = I•R where V=voltage applied I=current and R=resistance. How does that work exactly? how can you multiply two abstract concepts together to understand...

If I have (α1,β1,γ1) and (α2,β2,γ2) as two set of rotation angles in radians.Where α is Yaw of α about z axis, β is pitch about y-axis and γ is roll about x axis. My question is when I multiply the two rotation sets what would be the result? Would it be simple addition of angles if I extract the...

Can one set up a multiplication table for the symmetry group C3V of the equilateral triangle. Then show that it is identical to that of the permutation group P3. I need some clarification... What about a matrix representation (2x2) for these groups? → Here was thinking to use...

say X = (AB) (B-1 C) B-1 = B inverse (B B-1 = B-1 B = I) then can i write X = AC? just having a brain fart moment. i would appreciate a speedy response, cheers.

Hello, I'm not sure where to put this. I have spent the last week (14+ hour days) editing some code I have for selecting representative spectra for a remote sensing masters thesis I'm working on. The program is very-very slow, and I've been trying to speed it up as much as possible by NOT...

I understand that the cross product, in lay mans terms doesn't exist unless we're in 3 dimensions. When you multiply two matrices together I have been told you get something similar. I hear that this is because a matrix can be treated as a vector. So if we are talking about measurable...

Question: Let n be a positive integer and consider x,y,z to be elements of Zn. Prove that if x . y = 1 and x . z = 1, then y = z. (Since working in Zn the sign '.' means "multiplication modulo n".) Conclude that if x has an inverse element in Zn, then the inverse element is unique. Attempt...

Homework Statement This isn't homework, but I didn't know where else to ask and I have a test in an hour and a half. The study guide says be able to explain why statements like (A+B)^2 = A^2 + 2AB + B^2 are bogus when dealing with matrix's. Is it because (A+B) = (B+A) but (A+B)^2 /= (B+A)^2 or...