Integrating Definition and 971 Threads

  1. 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...
  2. 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
  3. 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...
  4. 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...
  5. 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...
  6. 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...
  7. 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...
  8. 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...
  9. 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...
  10. 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...
  11. 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...
  12. 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
  13. 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
  14. 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
  15. 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...
  16. 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...
  17. 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...
  18. 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 =...
  19. 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...
  20. 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...
  21. 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...
  22. 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 :)
  23. 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...
  24. 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?
  25. 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...
  26. Wellesley

    Integrating Factor for Exact Differential Equation

    I can see why y2 is an integrating factor, but I don't know how this answer can be derived. Do you use: \frac{N_{x}(x,y) - M_{y}(x,y)}{M(x,y)} Where M (x,y) = 4(x3/y2)+(3/y)]dx, and N = 3(x/y2)+4y dy When I try and solve this, I get a very complex integrating factor...
  27. P

    Integrating Over All Orientations: Solving Eqn (1)

    So I need to inegrate over a solid angle, in which every possible orientation is considered (we are doing scattering events in which we assume every possible angle is possible), thus I need to solve \int d\Omega_1 d\Omega_2 d\Omega_3 Eqn (1). Now I know \int^{2 \pi}_{0}...
  28. Z

    Integrating Torque With Force as a Function of Radius

    Homework Statement In this problem, I am asked to find the total torque acting on a device consisting of two open half-cylinders connected to a shaft rotating in a fluid. To clarify, they are half-cylinders in the sense that they have been cut in half in the lengthwise direction and are...
  29. R

    Integrating in polar coordinates (volume)

    Homework Statement The solid bounded by the parabolids z = 3x^2 + 3y^2 -7 and z = -x^2 -y^2 + 9 Homework Equations The Attempt at a Solution Ok so i set the two z equations into polar form and came up with 3r^2 = 7 and r^2 = 9 I thought that r went from (7/3) ^(1/2) to 3 and...
  30. R

    Integrating Factor: -g(m/g) and its Derivative

    In the following problem how does -g end up becoming -g(m/g)? Isn't the derivative of -g just (-g^2/2)? http://users.on.net/~rohanlal/integfact.jpg
  31. A

    Integrating a Constant Divided by a Linear Function of x

    Okay well, I looked through my calculus notes and textbook and I can't find what to do when you are integrating a function of the type a/u where a is a constant and u is some linear function of x. I know that the integral of 1/x is ln(x) but what about when you have something like \int...
  32. O

    Question integrating |f(z)||dz| over a contour C

    Homework Statement I want to compute \int_{C}^{}{|f(z)||dz|} along the contour C given by the curve y=x^2 using endpoints (0,0) and (1,1). I am to use f(z)=e^{i\cdot \texrm{arg}(z)} Homework Equations The Attempt at a Solution I know that for all complex numbers z, |e^{i\cdot...
  33. A

    Integrating 1/(2x^2 + 3x + 1)[(3x^2 - 2x + 1)^(1/2)]

    Homework Statement integrate Homework Equations 1/(2x^2 + 3x + 1)[(3x^2 - 2x + 1)^(1/2)] The Attempt at a Solution
  34. N

    Integrating Complexity: Indefinite Integral of e^(4x+(e^4x))

    Homework Statement Indefinite integral: e^(4x+(e^4x)) Homework Equations I'm thinking integration by parts, involving UV minus integral of Vdu The Attempt at a Solution So I saw that this can be split into two: e^(4x) times e^(e^4x)). The latter is a bit complicated. I...
  35. A

    I'm really having a problem integrating this equation, infact i have no idea

    Homework Statement Please tell me how to integrate this... Homework Equations [(2x + 4)][(2x^2 + 3x + 1)^(1/2)] The Attempt at a Solution
  36. H

    Integrating Trigonometric Functions with Irrational Exponents

    Homework Statement The integral from 0 to pi/2 of 1/(1 + (tanx)^sqrt2) dx. Homework Equations trig identities? The Attempt at a Solution I tried some substitutions but it just made the problem more complicated. I also multiplied by (tanx)^sqrt2 in the numerator and denominator in...
  37. B

    Mathematica Mathematica: Problems with integrating and plotting a function

    Hey, I have been trying to make Mathematica integrate the following function: r_{e}=\frac{c}{H_{0}}\int_{0}^{z}\frac{dz}{\left[\Omega_{NR}(1+z)^{3}+\Omega_n(1+z)^{3-n}+\Omega_{\Lambda}\right]^{\frac{1}{2}}} There are two cases for which this equation needs to be integrated, seperately; (i)...
  38. C

    How Can You Integrate xsinxcosxdx Using Exponential Form?

    How do you integrate xsinxcosxdx
  39. tony873004

    ODE, Integrating Factor method

    I'm trying to follow this example from class notes. x^2 \frac{{dy}}{{dx}} + xy = 1,\,\,y\left( 1 \right) = 2 Divide through by x^2 to set it up in a form for using the integrating factor method. \frac{{dy}}{{dx}} + \frac{y}{x} = - \frac{1}{{x^2 }} I'm not sure where the minus...
  40. D

    Integrating Exponential Functions to Solving e^(-(x^2)/2)

    Hi! I want to know how to intergrat e^(-(x^2)/2) . Someone told me to use the intergration of e^x= 1+ x + (x^2) /2!+ ...(X^n)/n! ... is that sounds right?? and if it is i got pi as an answer for e^(-(x^2)/2) , is that the right answer?
  41. A

    Sequence of functions; uniform convergence and integrating

    Homework Statement The sequence fn: [-1,1] -> R, fn(x)= nxe-nx2 converges pointwise to f(x)= 0, x in [-1,1]. Can you verify the following: limn->\infty (\int^{1}_{0}fn(x)dx) = \int^{1}_{0} (limn->\infty fn(x))dx Homework Equations Theorem: If fn is continuous on the interval D for every...
  42. K

    How Do I Integrate a WKBJ Semi-Classic Integral with a Square Root?

    Homework Statement I am having a problem integrating in a WKBJ semi-classic integral. Well it's this : I have to integrate \int_{0}^{\sqrt{m}E}\sqrt{E-\frac{x}{\sqrt{m}}}dx Homework Equations Actually I don't have that much experience at integrating, so could you somehow show me how to...
  43. S

    Integrating Equations with Exponents: A Challenge

    Homework Statement Homework Equations The Attempt at a Solution Homework Statement Homework Equations u = 1+tant du = sec^2(t) dt dt = du / sec^2(t) The Attempt at a Solution It seems like I should be using substitution in the equation, however the exponent is...
  44. M

    Integrating Int((5+10y^4)dy/(y+2y^5)) - A Step-by-Step Guide

    Homework Statement I want to deal with this int((5+10y^4)dy/(y+2y^5)) Homework Equations integration, substitution, partial fractions? The Attempt at a Solution I tried a bunch of random things. I think it hs to do with substitution because if I make u=y+2y^5, du/dy=1+10y^4...
  45. F

    Integrating v^2/v^2+4 - Exploring Arctan & u Substitution

    Homework Statement how do i integrate v^2 / v^2 + 4 Homework Equations i understand this has something to do with arctan but if i use u substitution to let v=(u/2) so (on the bottom) it becomes (1/4)(1+(v/2)^2) there's still a v^2 on the top which the u substitution does not...
  46. J

    Integrating Using Arctan: Solving for the Integral of 1/(x^2+11x+29)

    Homework Statement Integrate 1/(x2 +11x +29) Homework Equations The Attempt at a Solution I'm doing something wrong, but can't figure out what... Complete the square so that the denominator equals (x+2)2+25 Then divide by 25: ((x+2)2)/25 + 1 Move that 25 into the squared...
  47. E

    Integrating ln(t+1) from 0 to e^2x?

    Homework Statement How would I begin to integrate ln(t+1) from 0 to e^2x? Homework Equations d/dx[log base a of u]=1/(lna)u du/dx Can the original equation be manipulated to use this derivative? The Attempt at a Solution Not sure where to start.
  48. M

    Integrating from 0 to 200 of 1/(14-(.0003x^2))

    I can't figure out how to this integral. I keep coming up with the wrong answer. Can someone please show me a detailed solution?
  49. C

    Integrating dP/dr over the Sun

    Homework Statement Consider the Sun to be a sphere of hydrogen gas of uniform density equal to its average density (1440 kg/m3). a) Integrate the equation of hydrostatic equilibrium for dP/dr from the Sun’s radius to the core to estimate the central pressure in Pa and in atmospheres...
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