Recent content by ptolema
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Mathematical/Computational Biology - grad school
I do have some bio classes (1 year of general biology) and a summer internship involving genetics and computational bio. I've also picked up some bio from sitting in on classes and video lectures. Is there a particular area/course that they prefer?- ptolema
- Post #4
- Forum: STEM Academic Advising
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Mathematical/Computational Biology - grad school
I'm getting ready to apply to grad schools, and I'm having a hard time choosing schools to apply to. I'm an applied math major, and I'm really interested in mathematical/computational biology. I don't necessarily want to study math in grad school, but I'm open to math programs with a more...- ptolema
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- Biology Grad Grad school School
- Replies: 3
- Forum: STEM Academic Advising
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Finding maximum likelihood estimator
Homework Statement The independent random variables X_1, ..., X_n have the common probability density function f(x|\alpha, \beta)=\frac{\alpha}{\beta^{\alpha}}x^{\alpha-1} for 0\leq x\leq \beta. Find the maximum likelihood estimators of \alpha and \beta. Homework Equations log...- ptolema
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- Likelihood Maximum Maximum likelihood
- Replies: 6
- Forum: Calculus and Beyond Homework Help
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Solving a differential equation
Homework Statement Find the general solution: 2xy \frac{dy}{dx} = y + x^4Homework Equations The Attempt at a Solution I have tried to solve this as a linear first order equation, a Bernoulli equation, and an exact equation. I'm not sure how to approach this, any ideas?- ptolema
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- Differential Differential equation
- Replies: 1
- Forum: Calculus and Beyond Homework Help
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Why Must n Divide 6 When z^n and (z+1)^n Equal 1?
Homework Statement Let z be a complex number such that z^n=(z+1)^n=1. Show that n|6 (n divides 6) and that z^3=1. Homework Equations n|6 → n=1,2,3,6 The Attempt at a Solution The z+1, I think, is what throws me off. Considering z^n=1 by itself, for even n, z=±1 and for odd n...- ptolema
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- Complex Complex numbers Numbers
- Replies: 2
- Forum: Calculus and Beyond Homework Help
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Find integers A and B such that A^2 +B^2 = 8585
I see now. So 5, 17, and 101 are the factors of 8585. 5=2^2 + 1^2, 17=4^2 + 1^2, and 101=10^2 + 1^2. Using the Brahmagupta-Fibonacci identity yields the results shown.- ptolema
- Post #4
- Forum: Calculus and Beyond Homework Help
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Find integers A and B such that A^2 +B^2 = 8585
Homework Statement Find integers A and B such that A2 +B2 = 8585 Homework Equations The Attempt at a Solution So in this case, I already know the answer: Sum of 2 squares: 8585 = 67^2 + 64^2 = 76^2 + 53^2 = 88^2 + 29^2 = 92^2 + 11^2. I started off looking at the graph of the...- ptolema
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- Integers
- Replies: 3
- Forum: Calculus and Beyond Homework Help
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Using polar coordinates to find the distance traveled
I actually just tried it a different way. I used your suggestion, ehild, of drawing out the path. [PLAIN]http://www.privateline.com/Cellbasics/sevencellcluster.gif So the tourist travels in a path that traces the outside of this hexagon cluster. At least, this is how I ended up coming up...- ptolema
- Post #6
- Forum: Calculus and Beyond Homework Help
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Using polar coordinates to find the distance traveled
Yes, I understand that now. My problem is that although I can figure out the angle of the tourist after a given number of stages, I'm stuck on how to find the distance between the starting and ending points. When I do it graphically, I get a path that looks like partial traces of hexagons. The...- ptolema
- Post #4
- Forum: Calculus and Beyond Homework Help
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Using polar coordinates to find the distance traveled
Homework Statement A tourist takes a tour through a city in stages. Each stage consists of 3 segments of length 100 feet, separated by right turns of 60°. Between the last segment of one stage and the first segment of the next stage, the tourist makes a left turn of 60°. At what distance...- ptolema
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- Coordinates Distance traveled Polar Polar coordinates
- Replies: 6
- Forum: Calculus and Beyond Homework Help
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Express this series in terms of the given series A(x)
A(-x) = a0 - a1x + a2x2 - a3x3 + ... I see now. So when I add A(x)+A(-x), I get 2*E(x). Similarly, A(-x)-A(x) = -2*O(x). Thanks, your hint was a huge help!- ptolema
- Post #3
- Forum: Calculus and Beyond Homework Help
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Express this series in terms of the given series A(x)
Homework Statement Let A(x) = a0 + a1x + a2x2 + a3x3 + ... = Ʃanxn. Express E(x) = a0 + a2x2 + a4x4 + ... = Ʃa2nx2n. Do the same for O(x) = a1x + a3x3 + a5x5 + ... Homework Equations A(x) = a0 + a1x + a2x2 + a3x3 + ... = Ʃanxn The Attempt at a Solution So I tried using A(x2)...- ptolema
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- Series Terms
- Replies: 2
- Forum: Calculus and Beyond Homework Help
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Inequality proof: how many ways are there a1 =< =< ak =< n?
So you're saying that n integers have been partitioned into (k+1) element groups, just to be clear? Would it be nCk+1, then? Or rather, since the sets are ordered, nPk+1? Is it assumed that the set {a1, a2, ..., ak, n} may not have all distinct elements?- ptolema
- Post #3
- Forum: Calculus and Beyond Homework Help
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Inequality proof: how many ways are there a1 =< =< ak =< n?
Homework Statement Let k and n be positive integers. In how many ways are there integers a1≤ a2≤ ... ≤ ak≤ n. Homework Equations The Attempt at a Solution I don't really know where to begin. Simply using permutations doesn't seem to work. I know that for a1, there are n integers...- ptolema
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- Inequality Proof
- Replies: 4
- Forum: Calculus and Beyond Homework Help
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Induction: prove x^n + 1/x^n = 2cos(n*theta)
Homework Statement If a and theta are real numbers such that x + 1/x = 2cos(theta), then: x^n +1/x^n = 2cos(n*theta) Homework Equations x + 1/x = 2cos(theta) The Attempt at a Solution So I was able to show that the statement was true for n=1, but I'm stuck on how to even start...- ptolema
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- Induction
- Replies: 8
- Forum: Precalculus Mathematics Homework Help