Recent content by Beretta

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    Integrating Factor Method for Solving Differential Equations

    I solved it again I got (-cos2x)/(2xe^(x)) that (1/2)(1/x)(cos2x/e^x)
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    Integrating Factor Method for Solving Differential Equations

    Because the other way arround is too long, and I'm not that good to garanty free-mistakes in the backward if I couldn't in the forward.
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    Integrating Factor Method for Solving Differential Equations

    Hi all, Is the general solution of xy' + (1+x) y = e^(-x) sin 2x, y= (-cos2x)/(2xe^(x)) + c/(xe^(x)) Thank you very much guys
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    Solving Tangent Equation at Point P: r(t) = (t, t^2, t^3)

    Is it enough as an answer to the tangant equation to put the velocity in t=2? ie: r'(t) = [1i + 2tj + (3t^2)k] at t=2. T = 1i + 4j + 12k or should I leave it in the form of dexter's?
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    Solving Tangent Equation at Point P: r(t) = (t, t^2, t^3)

    Why did you chose t=2 please? I don't know how to put the point (2.4.8) in the equation. Is there any formula to plug the points into r'?
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    Solving Tangent Equation at Point P: r(t) = (t, t^2, t^3)

    Let C be the curve: r(t) = (t, t^2, t^3) in R3. Find the equation of the tangent line at P = (2,4,8). In this case should I calculate the unite tanget T= r'(t)/||r'(t)||? Or just the velocity r'(t) = 1i + 2tj + (3t^2)k? How to calculate the tangent equation at the point P?
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    Calculating Angular Velocity of a Pulley under Varying Force

    I keep thinking about rotation in terms of motion. Yes, radian/sec not m/s. I really appreciate all your help guys. Thank you very much.
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    Calculating Angular Velocity of a Pulley under Varying Force

    Do I need to go through this? Can't I just use \Delta \omega = \int_{0}^{2} \alpha(t) dt But do I need to subtract the initial omega that is given from the final omega? One more question please: when I did multiply the force equation by the radius, should I do the dot product or just...
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    Calculating Angular Velocity of a Pulley under Varying Force

    You mean intergrate in the Force to get K = 1/2 Iw^2? I'm a bit lost! What do you mean?
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    How to Calculate Distance in a Two-Stage Lift Journey Using SUVAT Equations?

    Since it started from rest V initial = 0m/s So first Velocity V= 0m/s + (0.5m/s^2)(t1) Second final velocity since it stoped 0m/s = V(initial) + (-0.75m/s^2)(t2 = 10s) and then you plug first Velocity in the second equation. 0m/s = [0m/s + (0.5m/s^2)(t1)] + (-0.75m/s^2)(t2 = 10s)
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    Calculating Angular Velocity of a Pulley under Varying Force

    A pulley of moment of inertia 0.021kg-m^2 and radius 0.12m is acted upon by a force which varies in time as F= 0.23t + 0.12t^2 where F is in Newton and t is in second. suppose that the pulley is initially rotating at 0.18 r/s and the force acts tangentially to the pulley. Find the magnitude of...
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    Solving Euler Equation for X^m (m^2 + 1)^2 = 0

    I did solve this differential equation (x^4)y'''' + 6x^3y''' + 9x^2 + 3xy' + y = 0 using Cauchy Euler Equation. I got X^m (m^2 + 1)^2 = 0 I'm not sure how to get the roots of (m^2 + 1)^2. In my calculation I got m = -i, +i, -i, +i when I put m^2 = -1. In the book they have m = (+-)...
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    Find the integral of x/(x-1)^2 with respect to x

    May you show me how I can elliminate the x please?
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    Find the integral of x/(x-1)^2 with respect to x

    I'm using this in differential equations I don't need the constant now.
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