Recent content by Amad27

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    MHB Can You Define the Recursive Equation for Strings of 1s and 2s with 3 Mod 4 1s?

    If $K$ is the set of strings of 1s and 2s with the number of 1s $\equiv3\bmod4$ and with any amount of $2$s, find a recursive definition of $K$. For example, $1112112121$. I'm in need of some hints. The string can be empty, have no 1's or have 1's equivalent to 3 mod 4...
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    Electron Velocity Diffraction Grating Problem

    Thanks. Okay:$$0.01\sin(3.6) = m\lambda$$ so m=1, and thus $$\lambda = 6.279*10^{-7} m$$ Then by De Broglie, $$\lambda = h/mv$$ Thus, $$v = \frac{6.63*10^{-34}}{(9.1*10^{-31})(6.279*10^{-7})} = 1.16 m/s$$ Is this right?
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    Electron Velocity Diffraction Grating Problem

    Homework Statement Suppose that visible light incident on a diffraction grating with slit distance (space) of $0.01*10^{-3}$ has the first max at the angle of $3.6^{o}$ from the central peak. Suppose electrons can be diffracted with this same grating, which velocity of the electron would create...
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    Where does the magnetic field go for the electron?

    I see. qv is negative right? So that is why you flip the direction?
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    Where does the magnetic field go for the electron?

    Okay. I see this now. So in general, should I always put the back of my hand on the page? For any problem? And then for the electron, just flip the direction while keeping the others same?
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    Where does the magnetic field go for the electron?

    I am actually very unfamiliar with that right hand rule. I use this one: So using this, I had the index pointing down and thumb pointing left, but that still had my middle finger pointing into the page?
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    Where does the magnetic field go for the electron?

    The charge is negative, but I already accounted for that by flipping the force and pointing my thumb to the left?
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    Where does the magnetic field go for the electron?

    Homework Statement **Question** Is the magnetic field directed into the page or out of the page?Homework Equations Right Hand Rule The Attempt at a Solution My index finger is pointing downwards, and since the magnetic force is towards the right and this is an electron (negative) my thumb...
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    MHB Find Remainder of $2^{100}-1$ Divided by 1000

    >Let $R$ be the set of all possible remainders when a number of the form $2^n$, $n$ a nonnegative integer, is divided by $1000$. Let $S$ be the sum of all elements in $R$. Find the remainder when $S$ is divided by $1000$. Here is my working:$2^{\phi(x)} \equiv 1 \pmod{x}$ such that $(2, x) =...
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    MHB Find the number of arrangements possible

    The Annual Interplanetary Mathematics Examination (AIME) is written by a committee of five Martians, five Venusians, and five Earthlings. At meetings, committee members sit at a round table with chairs numbered from $1$ to $15$ in clockwise order. Committee rules state that a Martian must occupy...
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    MHB Why do we subtract the combination?

    Problem: There are two distinguishable flagpoles, and there are $19$ flags, of which $10$ are identical blue flags, and $9$ are identical green flags. Let $N$ be the number of distinguishable arrangements using all of the flags in which each flagpole has at least one flag and no two green flags...
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    MHB Binomial Distribution Issue

    No, because in the first one, we multiply by $\binom{n}{k}$ because the order matters, doesn't the order also matter in the second one? I think I am messing this all up. Are you using these definitions to solve probability like this? Like the definition of hypergeometric distribution...
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    MHB Binomial Distribution Issue

    A test consists of 10 multiple choice questions with five choices for each question. As an experiment, you GUESS on each and every answer without even reading the questions. What is the probability of getting exactly 6 questions correct on this test? The answer is: $$\binom{10}{6} (0.2)^6...
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    MHB What is the sum of polynomial zeros?

    From Vieta's Formulas, I got: $a=2r+k$ $b=2rk+r^2+s^2$ $65=k(r^2+s^2)$ Where $k$ is the other real zero. Then I split it into several cases: $r^2 + s^2 = 1, 5, 13, 65$ then: For case 1: $r = \{2, -2, 1, -1 \}$ $\sum a = 2(\sum r) + k \implies a = 13$ Then for case 2: $r^2 + s^2 = 13$, it...
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    How to complete this derivative proof?

    @RUber, is my proof correct though?
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