Analysis and Calculus
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1111 topics in this forum
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I was wondering whether someone would be able to solve this equation by getting the maxima and minima and show the working: -3cos(4x-pi) I would attempt it, but i'm not quite sure how to go about it...thanks.
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Reputation Points
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i need to evaluate the follows integral: [math]\oint dy (A' e^{A})' [/math] where ' is derivation respect [math]y[/math] and [math]A(y)=A(y+2\pi)[/math] and too [math]A(y)'=A(y+2\pi)'[/math] where [math]y \in (-\pi,\pi)[/math] ia a angular coordinate , and [math]A' [/math] is discontinuous in [math]-\pi,0,\pi[/math] the result is zero, but i think that is NOT CORRECT to say: [math]\oint dy (A' e^{A})' = A' (\pi)e^{A(\pi)}- A' (-\pi)e^{A(-\pi)} =0 [/math], since [math]A' [/math] is discontinuous in -pi and pi
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f:R-->Q show that there is a q \in Q such that f^-1(q) is infinite set in R ?????
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Suppose we were given the following inequality :[math]\frac{x-2}{x}>x+1[/math] ,and the following two solutions were suggested: Solution No 1: for x>0 the inequality becomes (after multiplying across):[math]x-2> x^2 +x[/math] ,or [math] 2+x^2<0[/math],but since [math]2+x^2\geq 0[/math] we have a contradiction ,hence the inequality is satisfied for all x<0 Solution No 2:[math]\frac{x-2}{x}>x+1\Longleftrightarrow\frac{x-2}{x}-(x+1)>0[/math] . And working on the left hand side of the equation we have : [math]\frac{-2-x^2}{x}>0[/math] ,or [math]\frac{2+x^2}{x}<0[/math],and since [math]2+x^2\geq 0[/math] we conclude that x<0…
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Reputation Points
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I was wondering how you integrate - with simply the integral of the power rule (n^x)' = nx^n-1, when the equation, such as (15x^3 + 8x^2 - 5/x) doesn't have any multiples for the antiderivative of 15x^3 or 8x^2... do you just leave them or something...
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Reputation Points
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[math] ax^2 + bx + c = 0 [/math] is general form by using factorisation, we can turn it into this form let's say... [math] (x - r_1)(x + r_2) = 0 [/math] then we get the roots as follow [math] x - r_1 = 0 [/math] [math] x = r_1 [/math] & [math] x + r_2 = 0 [/math] [math] x = - r_2 [/math] compare to forming an equation out of roots(where roots are given) it's different story, where it's giving me some headache to think about... usually, teacher will give formula [math] x^2 - (S.O.R) + (P.O.R) [/math] S.O.R = sum of root P.O.R = product of root but, I personally don't like remembering and plugin stuff in ma…
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Any suggest about how to solve this ecuation will be appretiated [math] x(\csc(x)+1)=\pi[/math] Thanks in advance.
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This might be a dumb question but when solving ODE's with scilab and you set the independent variable points at which you want to evaluate, what is the middle number used for in t = 0:0.1:5 for the example: function dx = f ( t , x ) dx = sin (2 t ) ; endfunction t0 = 0 x0= -0.5 t=0:0.1:5; x = ode(x0, t0, t, f); plot2d(t, x) Here's the link for the example: http://scilab.in/files/workshops/15-04-2010-mumbai/sengupta-ode.pdf Thanks for the help!
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prove that the following sequence converges: [math]x_{k+2} =\frac{2}{x_{k+1} + x_{k}} ,x_{1},x_{2}>0[/math]
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Reputation Points
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I was solving some differentials for practice, and the final question I was given was [math] (x^2-1) \frac{dy}{dx} = xy [/math] I went about solving this by doing (some steps missed out): [math] \int\frac{1}{y}dy = \int x^3-x dx [/math] [math] ln(y) = \frac{2x^4-4x^2}{8}+k [/math] And then, I was left with this, extremely irritating answer, which didn't look right at all, and incidently, wasn't right: [math] y = Ae^\frac{2x^4-4x^2}{8} [/math] Note: A = ek I don't think I've done anything wrong with the integration, I just have a feeling there's a way to simplify this that I don't know. Any suggestions please: I need to learn! ADDITION: …
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Reputation Points
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I'm not fantastic at integration, but I can integrate any number of polynomials pretty easily. I was given the equation "y=x(3-x)" to integrate. so I naturally treated it as a factorised quadratic, expanded it, and did: Int.(-x2 + 3x)dx = -1/3x3 + 3/2x2 I therefore assumed that: Int.(-x2 + 3x)dx = Int.(x(3 - x))dx It turns out i was wrong, and that I can't just expand these brackets, as the actual answer is (according to an integral calculator): -((2x3 - 9x2)/6) I need to know why I can't just expand these brackets and integrate, and how to integrate a factorised quadratic like this one. Please help me I also don't think a "u" substitu…
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Reputation Points
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I'm doing a biology lab and was wondering, a basic version is this I can either put 0 1 or 2 of two types of organisms in a test tube and the test tube can then either be put into the dark or the light. I was wondering how many test tubes I will need to conduct this experiment. I'm thinking that you would multiply 3 by 3 by 2 because there are 3 possible number of each organism and their is 2 places they could be put. If someone could explain how to do this type of problem I would be very grateful. I don't actually need to fill all possibilities, just enough to answer some lab questions, which I have answered before I did anything. I was just wondering what the formula wo…
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Hope this is in the right section. Having trouble ironing out an apparent inconsistency in matrix trace derivative rules. Two particular rules for matrix trace derivatives are [math]\frac{\partial}{\partial\mathbf{X}} Tr(\mathbf{X}^2\mathbf{A})=(\mathbf{X}\mathbf{A}+\mathbf{A}\mathbf{X})^T[/math] and [math] \frac{\partial}{\partial\mathbf{X}} Tr(\mathbf{X}\mathbf{A}\mathbf{X}^T)=\mathbf{X}\mathbf{A}^T+\mathbf{X}\mathbf{A}[/math] Now assume that [math]\mathbf{A}[/math] is diagonal and [math] \mathbf{X}[/math] is anti-symmetric. Then by the cyclic property of the trace, [math]-Tr(\mathbf{X}^2\mathbf{A})=Tr(\mathbf{X}\mathbf{A}\mathbf{X}^T)[/math]. So t…
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My question is how to compute R(dx). But before I can ask that I have to write down the background to my problem, so bear withme ---------------------------------------------------------------------------- A tempered stable distribution is when a stable distribution is tempered by an exponential function of the form [latex]e^{-\theta{x}}[/latex]. In my particular case we are using a tempered stable law defined by Barndorff-Nielsen in the paper "modified stable processes" found here, http://economics.oul...nmsprocnew1.pdf. In Barndorff's paper, [latex]\theta = (1/2)\gamma^{1/\alpha}[/latex], hence the tempering function is defined as [latex]e^{-(1/2} \gamma^…
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I'm struggling to work out how to integrate the following [latex]\int_0^t(\gamma^{1/\kappa}-i\zeta{w}(1-t/s)_+^{H-1/2})^{\kappa}ds[/latex] here (.)_+ denotes the positive part if I did not have the ^(H-1/2) I can do it, alas it does have it! and so it stumps me on how to evaluate this integral. any advice much appreciated
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based on the example 2 in this website why does the normal equation doesn't perpendicular to the tangent? or i do any calculation wrong?
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There was a post a while back on "1/0", and I was disappointed to see a post of mine deleted. So I'll be brief and repeat my previous remark. While 1/0 is generally undefined for fields, it is defined on the Riemann Sphere for the so-called extended complex numbers. On this complex manifold, 1/0 = [tex]\infty[/tex], the "point at infinity". Wolfram|Alpha and Mathematica implement this sort of complex arithmetic, albeit a bit inconsistently. Here's what Wolfram|Alpha thinks 1/0 is: http://www.wolframalpha.com/input/?i=1%2F0
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While reviewing basic calculus, I noticed that the curve (1+t^2,t^2,t^3), which clearly has a cusp at (1,0,0), has a derivative curve (2t,2t,3t^2) which is clearly smooth. This struck me as odd since differentiation usually seems to turn cusps into discontinuities, whereas integration smoothes out a curve, especially a curve described by polynomials. In fact, in general I have always taken a curve to be smooth iff it has a continuous derivative, which this curve has, and yet a cusp cannot be smooth in any sensible sense. I suspect the explanation is relatively simple - just something I'm missing. Thx in advance.
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I just learned that the normal distribution is the solution to [math] \frac{\mathrm{d}y}{\mathrm{d}x}+yx = 0 [/math] What problem led to this differential equation? How does this equation lead people to think of distributions? In a "real" world problem (physics) what could [math]y[/math] and [math]x[/math] be?
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Question: Let A =(1+R)〖(-4+R^2)〗^2 B =〖(6+4R+B^2 R-5R^2-R^3+R^4+B(R^2+R-2))〗^2 C =(1+γ)〖(-4+γ^2)〗^2) D =〖(6+4γ+β^2 γ-5γ^2-γ^3+γ^4+β(γ^2+γ-2))〗^2 ) I need to prove that A /4B - C /9D > 0, given 0 < γ < R < 1, 0 < β < B < 1. How to do it? If I can use Mathematica to help, that will be great too. What I am thinking now is to find the Minimum of (A /4B - C /9D). If the minimum >0, then A /4B - C /9D >0. Is that a right direction to go? How can I write the input code for this including the constraints 0 < γ < R < 1, 0 < β < B < 1? Thank you so much for any hints or help!
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before getting started... i know how to use discriminant for Quadratic Equation/Function which is when [math] b^2 - 4ac > 0 [/math] so, the root(x) would have 2 intersect point and [math] b^2 - 4ac = 0 [/math] so, the root would have 1/equal intersect point and [math] b^2 - 4ac < 0 [/math] so, there are no root. but, I can't get the relation between those.. I mean, why [math] b^2?[/math], why [math]-4?[/math] why a and c?, why > or = or < ??? http://www.coolmath....arabolas-01.htm this website give me good concept of understanding the Quadratic Equation/Function in General Form/Vertex Form, but I found none for 'discriminant' w…
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Okay, in the Escape Velocity Equation, with the usual notations, v2=2gR2/r + (v02-2gR) a few articles like www.math.binghamton.edu/erik/teaching/02-separable.pdf and http://www.uv.es/EBR...5000_17_84.htmlgive the following explanation: ... ... ...(implying that v0>=√2gR) That raises a few doubts in my mind: (1)Does the term 2gR2/r become zero? (2) If the answer to (1) is yes(i.e. 2gR2/r=0), then how come v0 is allowed a value equal to √2gR?(since, substituting v0=√2gR in the original equation(i.e. v2=2gR2/r + (v02-2gR)) will yield v=0(which is obviously not desired if a particle has to escape the Earth) (3)If the answer to (1) is no(i.e. 2gR…
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I'm trying to solve this function. [math] = \frac{1 + (\frac {2x + 3}{3x- 4})}{(\frac {4x + 6}{3x-4}) - 3} [/math] [math] = \frac{\frac {2x + 3 + 3x -4}{3x- 4}}{\frac {4x + 6 - 9x +12}{3x-4}} [/math] [math] = \frac {5x - 1}{3x- 4} / \frac {-5x + 18}{3x-4}[/math] [math] = \frac {5x - 1}{3x- 4} * \frac {3x-4}{-5x + 18}[/math] [math] = \frac {5x - 1}{1} * \frac {1}{-5x + 18}[/math] [math] = \frac {5x - 1}{-5x + 18}[/math] but how come mathematica got this? mathematica 1 mathematica 2 where does the " -1 " came from???
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