Integrating Definition and 940 Threads

  1. P

    Integrate Volumes: Revolve Region Bounded by x=0, x=1, y=0, y=x^5

    Homework Statement Revolve the region bounded by x=0, x=1, y=0 and y=x^5 about the y-axis use shells to find the volume I know how to set up the integral I just don't know where I'm integrating from. Is it from 0 to 1?
  2. M

    Integrating a quadratic funtion raised to m/n

    I couldn't figure out what to do with this type of integration \int (a x^{2}+ bx +c) ^{\frac{m}{n}}dx here m, n are integer numbers. Integration limit -∞ to +∞. Will Binomial expansion work? Please give me some clue.
  3. C

    Integrating exp(x^2) like gaussian integral?

    Integrating exp(x^2) like gaussian integral?? Hi, I can't solve this integral \int^{1}_{0}\\e^{x^2}\\dx Can I solve this integral like gaussian integral? Please help me Thanks.
  4. P

    Change of limits when integrating with polar coordinates

    Homework Statement ∫ e^(\pix^2) dx, with limits -∞ to ∞ Homework Equations ∫∫ dxdy = ∫∫ rdrdθ The Attempt at a Solution Hi, here's what I've done so far: Introduce a dummy variable y to get ∫∫ e^\pi(x^2 + y^2) dxdy, with limits -∞ to ∞ for both dx and dy...
  5. M

    How Do You Integrate 59x(cos(x))^2?

    Homework Statement \int 59x(cos(x))2 dx Homework Equations The Attempt at a Solution I tried doing integration by parts with u= (cos(x))2 and dv= xdx v= \frac{x^2}{2} However this didnt get me very far can some one tell me what the first step or two are.
  6. G

    What is the reason for different integrals if equations are the same?

    I am a little confused here. If the integral of f'(x)/f(x)= ln|f(x)| +k then say the below equations which are the same give different results? 2/(2x+2) The top is a derivative of the bottom, so the integral is ln|2x+2|+k 1(x+1) This is the same as the first equation. The top is also...
  7. S

    MATLAB Fixing Problems Integrating Function in MATLAB

    Hey I'm having problems trying to integrate my function func1 in MATLAB. Really don't know where I am going wrong so would really appreciate if anyone could help. The code I'm using is below, thanks: Function Mfile: function [ f1 ] = func1( E, Delta, kB, Temp ) %func1: calculates...
  8. O

    Integrating 1/(4+x^2)^2 dx: How to Use Trigonometric Substitutions

    I'm supposed to be Integrating 1/(4+x^2)^2 dx using trigonometric substitutions, but I do not know how to get started with this one. Am I supposed to rewrite this as 1/sqrt((4+x^2)^2) and then use the reference triangle? I've tried expanding the bottom, but that doesn't get me anywhere...
  9. Q

    Integrating Power Series for a Function

    Homework Statement Find a power series representation for the given function using termwise integration. f(x) = \int_{0}^{x} \frac{1-e^{-t^2}}{t^2} dt Homework Equations The Attempt at a Solution Well, I figured I could rewrite it like this using the Maclaurin series for...
  10. N

    Finding the integrating factor (ODEs)

    Finding the integrating factor (ODEs) [Solved] Working on this problem, I can't figure out why we take the derivative of \mu with respect to y, and what to do when our integrating factor is a function of both x and y. In the case below, it ended up being separable, but what can you do if it's...
  11. M

    What is the correct notation for integrating F(x)?

    Hi, this isn't a homework question, I'm just curious about this. I am wondering what the correct notation is for the integral of F(x). For example, integral of f''(x) = f'(x) + c integral of f'(x) = f(x) + d integral of f(x) = F(x) + e integral of F(x) = ?? I feel silly for not...
  12. O

    Integrating a vector valued function

    Homework Statement Calculate \int _{\mathbb{R}^{3+}} V(\textbf{r} ) d\textbf{r} where V(\textbf{r})=\frac{1}{r},\ \ r=||\textbf{r}|| The Attempt at a Solution I'm guessing \textbf{r}=x \textbf{i} + y \textbf{j} + z \textbf{k} so r=\sqrt{x^2+y^2+z^2} and d\textbf{r}=...
  13. A

    1st order linear differential equations - integrating factors

    Hi guys, this is my first post but have read the forums for a long time - a quick search didnt bring up anything that could help me. So i was wondering if someone could please explain something to me. I have a differential equation (excuse the pictures, I don't know how to use the equation...
  14. K

    General Solution of dy/dt = -2ty + 4e^(-t^2) w/ Initial Value Problem

    For the first question, I am only supposed to find the general solution of the differential equation. 1) dy/dt = -2ty + 4e^(-t^2) dy/dt + 2ty = 4e^(-t^2) Integrating factor = e^(Integral of 2t) = e^(t^2) Multiply both sides by IF: e^(t^2) * (dy/dt +2ty) = 4e^(t^2-t) e^(t^2)*dy/dt...
  15. I

    What is the Integrating Factor for Solving this Differential Equation?

    Homework Statement Solving this differential equation ty' + 2y = t^2 - t + 1 Homework Equations Its linear so i set it up in linear form y' + y(2/t) = t - 1 +1/t The Attempt at a Solution the integrating factor (u) = e ^ integral (ydt) = e^ integral (2dt/t)... Here's the...
  16. M

    Integrating Partial Fractions: Solving a Challenging Integral

    Hello :smile: I've been stuck on this question for almost 3 hours now, and I still have no idea what to do. We haven't done a question like this in class, although we have done integration with partial fractions. Homework Statement Evaluate...
  17. J

    Integrating dq to find that q(r) = Q(1-e^(-r/R))

    Homework Statement provided with data that dq = rho(r) *4phi*r^2*dr rho(r) = [Q*e^(-r/R) / 4phi R *r^2) I have to show that the charge q(r) enclosed in a sphere of radius r is q(r) = Q(1-e^(-r/R)) by using appropriate integral. how the integral should be? Homework Equations The...
  18. Z

    Integrating with U-substitution

    Homework Statement Find the integral of (1-x)((2x-x^2)^.5) dx Homework Equations The Attempt at a Solution I am kind of hazy on U substitutions but I thought that was the right way to go here: let u=2x-x^2 du=2-2x (1/2) Integral of (u)^.5 du < i wasn't sure if I went wrong...
  19. CFDFEAGURU

    Differential Equation using Integrating Factor

    Homework Statement The ODE is (1+x)*dy/dx - xy = x+x^2 Homework Equations The method of solution is to be through the use of the integration factor. The Attempt at a Solution First, I divided each side by (1+x) to produce dy/dx - xy/(1+x) = x then factor out the x on...
  20. K

    Integrating with Partial Fractions - Irreducable

    Homework Statement I need to integrate (2x-5)/(x^2+5x+11) Homework Equations The Attempt at a Solution My problem is just finding a formula for an irreducable quadratic. I know if the denominator was x(x^2+1), I would use A/x+(Bx+C)/(x^2+1). I just don't know the formula in this...
  21. K

    Do Equations of the Form P(x,y)dx+Q(x,y)dy=0 Always Have an Integrating Factor?

    During one lecture it was mentioned that equations of the form P(x,y)dx+Q(x,y)dy=0 always have at least one integrating factor. But the lecturer didn't know the proof, I've tried using Google but no luck. Anybody can show me the proof? Thanks a lot.
  22. C

    Integrating angular damping into angular velocity and rotation

    I'm using a 3rd party physics engine to run rigid body physics. It just updates the bodies once every 16 ms or so. I'm trying to write an algorithm to predict where free-falling bodies will be in 2 seconds using standard physics equations. I'm having trouble with predicting angular velocity and...
  23. A

    Integrating products of Bessel functions

    Hi guys, Does anyone have any ideas about an analytical solution for the following integral? \int_{0}^{2\pi}J_{m}\left(z_{1}\cos\theta\right)J_{n}\left(z_{2}\sin\theta\right)d\theta J_{m}\left(\right) is a Bessel function of the first kind of order m. Thanks.
  24. M

    Integrating 2nd order derivative

    The question is If f(x) = 7x^3 + 8x^2 - x + 11, evaluate : a, Integral +1 - -1 f(x) dx b, Integral +1 - -1 f'(x) dx c, Integral +1 - -1 f''(x) dx For a, Just integrate each individual and then input the figures which gave me 1.75x^4 + (8x^3)/3 - 0.5x^2 + 11x Which when I input...
  25. S

    Integrating Difficult Equations: U Substitution

    Homework Statement As I was reviewing some of my previuosly learned calculus I came across somthing that I had either forgoten how to do or was never taught. How do you take the integral of somthing like this \int \sqrt{\frac{9}{4}x+1} I don't know how to start with this one. Do I use U...
  26. S

    How to Integrate d^2 x or d^3 x in Physics?

    Hi Guys, Ive gone through a 3 year physics degree but can't remember ever touching on this? I am doing some work and some of the theory contains integrals of d2x or d3R for instance. I have no idea how to do these. Any help? Thanks all
  27. K

    Maple Why Does Maple Return Symbolic Answers When Integrating Functions?

    Hi every body I am trying to intergrate the following function using Maple: j2out(x):=c2*x*exp(int((s-vout(s))/s/vout(s),s=0.0015..x)); where vout(s)=0.07595560773650. C2 is constant but when I do, it returns a symbolic answers i.e Maple just returns the original expression without...
  28. Y

    Integrating the Paraboloid: Finding y^2z^2

    Homework Statement Find \int\int\int y^2 z^2where E is the region bounded by the paraboloid x = 1 - y22 - z2 and the plane x = 0. The Attempt at a Solution The region is a paraboloid with vertex at x = 1, y = 0, z = 0. I chose z bounds to be between 0 and 1 - y22 - z2 for first integral...
  29. H

    Integrating Factors Found by Inspection

    I need some explanation regarding a solution found in our textbook. The example starts with this DE: (1) y(x3 - y)dx - x(x3 + y)dy = 0. By regrouping, exact DEs will be found and the equation can be rewritten to: (2) x3 d(\frac{x}{y}) - \frac{d(xy)}{y} = 0. The integrating factor is found...
  30. R

    Integrating Log[1+x] using Series Expansion

    Homework Statement Integrate: \frac{Log[1+x]}{1+x^{2}} Homework Equations Integration by parts. The Attempt at a Solution If the integration is easier than what I think. Please let me know how to get started. I used integration by parts to get uptil here...
  31. C

    Integrating the square root of a linear function.

    Homework Statement \int\sqrt{2*x-1} Homework Equations The Attempt at a Solution Homework Statement Obviously this can be fixed with the antiderivative of a linear function with proper constants i.e. \int A\times f(bx + c) = \frac{A}{b} F(bx + c), however my instructor provided...
  32. C

    Is Integrating for pi the Best Method for Calculating Accurate Values of Pi?

    I was thinking about how to approximate pi accurately and came up with something and all the calculations i did seem to show that its true and I am wondering if its used often for calculating pi or if there is something better? radius of this circle equals 1 and therefore calcualting a...
  33. I

    Problems with integrating and Deferential equation

    Homework Statement give the general solution of the following equation x' = tx + 6te-t2 Homework Equations for x'+p(t)x=q(t) xeI=\intq(t)eIdt where I=\intp(t)dt integration by parts \intf'g = [fg] - \intfg' The Attempt at a Solution x'-tx=6te-2t I=\int-t dt = -t2/2...
  34. T

    Integrating Sec Tan^2: Solving the Square Root of (x^2-1) over the Interval 0-1

    Homework Statement Integrate the square root of (x^2 -1) over the interval 0-1. The attempt at a solution First off, I know this is a quarter of a circle, but I'm not supposed to solve it that way. Now then: x = sec theta dx= sec tan theta. square root (x^2-1) dx becomes...
  35. Mentallic

    Integrating: \int{\frac{xsec^2x}{tanx+\sqrt{3}}}dx

    Homework Statement \int{\frac{xsec^2x}{tanx+\sqrt{3}}}dx The Attempt at a Solution I let tanx+\sqrt{3}=u Then, \frac{du}{dx}=sec^2x , dx=\frac{du}{sec^2x} Substituting into the integral: \int{\frac{x}{u}du But now I don't know what to do. That little x is really screwing me...
  36. D

    Integrating the Complex conjugate of z with respect to z

    Im doing a bit of contour integration, and a question came up with a term in it am unsure of how to do: in its simplest form it would be \int\bar{z}dz where z is a complex number and \bar{z} is it's conjugate. Hmm i can't get the formatting to work out properly.. :S
  37. C

    Integrating the delta function

    Homework Statement By using the substitution u=cosx obtain the value of the integral \int\delta(cosx-1/2)dx between 0 and pi Homework Equations I have no idea how to go any further with this apart from substituting in for u!? The Attempt at a Solution
  38. T

    Understanding Thermodynamics: Demystifying the Chain Rule for Integration

    I am reading a thermodynamics book. I am confused on how they say use the chain rule Here. it makes no sense to me how they go from dV/dt to (dV/ds)(ds/dt) . I know how the chain rule works ,just don't know where they got these values
  39. J

    Solving a Grad f Statement: Finding, Evaluating, and Integrating

    Homework Statement grad f = (3x2 + y2)i + (2xy - 3)j a) find f b) evalue the integral of grad f dot dr where c is any path from 1,2 to 2,1 c)evaluate the integral of gradf dot dr where c is the curve given by 4x2 + 9y2 = 36 Homework Equations The Attempt at a Solution...
  40. N

    Techniques for Integrating Radical Functions?

    What are some techniques for integrating functions that are or contain radicals? I am familiar with trigonometric substitution. Are there any other "common" techniques or special functions that can be used to integrate these functions? or does trigonometric substitution basically take care of...
  41. C

    How Do You Integrate w/(w^4 + 1)?

    I'm supposed to integrate w/w^4 + 1 The two ideas I'd come up with was trying to substitute w^4+1 with u but that results in a 0 in the numerator. Then I thought maybe I have to put w/w^4+1 into the 1/1+w^2 form and integrate into 1/k tan^-1kx + C but I'm not sure how to keep the original...
  42. S

    How to Approach Complex Integral Calculations in Homework?

    Homework Statement 1.) \int{\frac{t}{(1+t^{2})^3}dt} 2.) \int{xe^{-2x}dx.} 3.) \int{\frac{x.dx}{2+x^{2}}} This one is inegrating between 2 and 0, but I didn't know how to format that in. 4.) \int{\frac{cos t}{1 + sin t}dt.} Homework Equations Q 1.) I'm substituting u =...
  43. N

    Complex Analysis: Integrating rational functions

    Homework Statement Hi all. My question has to do with integrating rational functions over the unit circle. My example is taken from here (page 2-3): http://www.maths.mq.edu.au/%7Ewchen/lnicafolder/ica11.pdf We wish to integrate the following \int_0^{2\pi } {\frac{{d\theta }}{{a + \cos...
  44. E

    How Do You Calculate the Line Integral of a Vector Field Along a Segment?

    Homework Statement say I have \vec{F} = ye^x\vec{i} + e^x\vec{j} and C the line segment from the point (1,4,-2) to the point (6,7,-2).I need to find: \int\limits_C \vec{F} d\vec{r} Homework Equations The Attempt at a Solution First I parametrize C as: \vec{r} = 6 + 5t \vec{i} + 7+3t...
  45. B

    Integrating to find volume of an unusual shape

    is there an exact way to calculate the volume of a shape where one shape is revolved around a parabolic curve (obviously with limits). i don't know much about this stuff but I am pretty sure u need to integrate it. the shape revolved is a rectangle (vertical) with a triangle connected at the...
  46. F

    Integrating Exponential Functions - Solving by Parts

    (x^2).e^(-2a(x^2)) how would i integrate this? By parts? If so using |udv = uv - |vdu (hope that's right) would i let u = x^2 and dv = e^(-2a(x^2)) ? but how do I integrate dv = e^(-2a(x^2)) to find v ? any help appreciated :)
  47. B

    Integrating a non-elementary function

    Homework Statement Integral (pi1/2, 0) of Integral (pi1/2, y) sin(y2) dxdy Homework Equations This one is interesting because it can't be integrated as is (at least not at the level of my course) but I think with some rearranging it can be done. I was wondering if anyone could verify...
  48. S

    Problem with integrating factor

    what next ? TNX !
  49. M

    Integrating a differential equation

    Homework Statement y' = 2xy/(x^2-y^2) answer: Cy = x^2 + y^2 Homework Equations The Attempt at a Solution dy/dx = 2xy/(x^2-y^2) dy = [2xy/(x^2-y^2)]dx how do i separate the variables?
  50. H

    Integrating the inverse square law

    Hi, I am trying to solve the following problem (but note you can skip the details and look at the last equation and help me with the integral): a small planet (mass m) is found at rest relative to the Sun (mass M) with a separation distance x_{0}. Consider now the small planet move in response...
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