Integrating Definition and 971 Threads

  1. B

    Triple integrating cylindrical coordinates?

    Homework Statement Integrate the function f(x,y,z)=−4x+3y over the solid given by the figure below, if P = (5,1,0) and Q = (-5,1,2). [PLAIN]http://img259.imageshack.us/img259/958/sfig1681g1.gif Homework Equations x=rcos(\theta) y=rsin(\theta) r=sqrt(x^2+y^2)The Attempt at a Solution i...
  2. B

    Integrating a function involved error functions and a Gaussian kernel

    I am currently facing a problem of integrating exp(-ax^2)*erf(bx+c)*erf(dx+f) with the integral boundaries 0 and infinity. I have gone through some handbooks but what I could locate is the integration of exp(-ax^2)*erf(bx)*erf(cx) from 0 to infinity which yields...
  3. I

    Integrating Vector Fields on a Sphere

    Homework Statement Given two vector fields: i) A \frac{\vec{r}}{r^{n_{1}}} ii) Ae_{z} \times \frac{\vec{r}}{r^{n_{2}}} where A is a constant and n_{1} \neq 3 and n_{2} \neq 2 find \int \vec{F} dS through surface of a sphere of radius R Homework Equations \int \vec{F} r^{2}...
  4. T

    Integrating e^(2 theta)sin(9 theta) d theta

    Homework Statement Integrate. \int e^{2\theta}sin(9\theta) d\theta Homework Equations Integration by Parts \int udv = uv - \int vduThe Attempt at a Solution I started out with integration by parts (IPB). u = e^{2\theta} du = 2e^{2\theta} d\theta v = \frac{-1}{9}cos(9\theta) dv =...
  5. T

    How do you integrate tan^5(x)?

    Integrating tan^5(x)... [UNSOLVED] Homework Statement \int tan^5(x) dx Homework Equations tan^2(x) = sec^2(x) - 1 The Attempt at a Solution First I split it up into (3+2). \int tan^3(x)tan^2(x) dx Using the identity for tangent squared... \int tan^3(x)(sec^2(x) - 1) dx...
  6. M

    Integrating a set of data points

    Homework Statement I have a set of data points, and I need to find the area under the curve they form. I am trying to use Maple for this, by using the PolynomialInterpolation() to fit a curve to my list of points. I then would just integrate this function over the appropriate interval...
  7. C

    Integrating square roots with trig function and constant inside

    Homework Statement ∫√(2+cos3(t)) dtI should perhaps have tried to get the lower and upper limits of this integral (it's defined), but all I'm wondering about is how to calculate the integral. I don't need the answer, but if someone could just point me in the right direction. I've tried...
  8. T

    Integrating product of bessel function,

    Hallo there. I m trying to integrate a bessel function but with no great success... I thing it can't be calculated.. I m trying to simulate the airy pattern of a certain aperture radius and wavelength in matlab. the integral is : int (besselj(1,16981.9*sin(x)))^2/ sin(x) dx where you can...
  9. T

    Integrating product of bessel function,

    Hallo there. I m trying to integrate a bessel function but with no great success... I thing it can't be calculated.. I m trying to simulate the airy pattern of a certain aperture radius and wavelength in matlab. the integral is : int (besselj(1,16981.9*sin(x)))^2/ sin(x) dx where you can...
  10. D

    Integrating non-constant acceleration to give time

    Homework Statement Not specifically a homework assignment, but for a personal project - but it's almost entirely parallel with my Physics course at the moment, and is mostly a homework-style question! I have an object acclerating due to a force, experiencing friction. Both the accelerating...
  11. J

    Integrating a Scalar Map over a Compact Manifold: What's So Special About It?

    First let me write out the definition of a manifold given in my book: Let k > 0 . A k-manifold in \mathbb{R}^n of class C^r is a subspace M of \mathbb{R}^n having the following property: For each p \in M , there is an open set V \subset M containing p , a set U that is open in...
  12. P

    Why Does the Sine Function Vanish in This Trigonometric Integration?

    I couldn't figure out how (*) derived. How can the underlined part's sine function vanishes? http://img149.imageshack.us/img149/8642/asfdg.png Uploaded with ImageShack.us
  13. K

    How to Integrate the Equation (b1-(b1*x/L)+(b2*x/L))^2 with Respect to x?

    Homework Statement Integrate Homework Equations integrating following equation about dx: (b1-(b1*x/L)+(b2*x/L))^2 The Attempt at a Solution I expanded all terms than integrated. I used integration by part to get it down to this but I am curious to see if there's better way to...
  14. T

    Differential equations question - possible integrating factor?

    Homework Statement Solve the differential equation with the initial condition y(0) = 1 Homework Equations 3e5xdy/dx = -25x/y2 The Attempt at a Solution First I tried putting everything with an x or dx on one side and a y or dy on the other side, and solved for C. I got 0 as the...
  15. R

    Integrating f(x) with Trapezium Rule & Plotting for Different Values of C

    Homework Statement Write a script file to integrate the function f(x)=x^3+tan(x)+C using the trapezium rule.Calculate the integral between the end points x=2 and x=4 with strip size 0.1.Calculate the integral for range of values from 1 to 3 in steps of 0.1.plot the integral obtained for...
  16. Rasalhague

    Integrating 2-forms over a parameterised surface

    Not sure if this question belongs more here or in Topology & Geometry or in Math & Science Software... I'm trying out the technique described in Bachman: A Geometric Approach to Differential forms, § 6.2 "Integrating 2-forms". To take a simple example, I tried to use this method to get the...
  17. C

    Integrating to find Volume (different from the other guy)

    Ok so I'm doing my online homework and I came across this problem: "Find the volume of the solid obtained by rotating the region bounded by the given curves about the specified line. y=11, y=x+28/x about x=-4" So I attempted to...
  18. S

    Integrating 1/x*e^x dx from 0 to s, how to do it

    Hi I have an integral as follows, int((1/x)exp(-x),x,0,s) I want to integrate from [0,s). My question is how to integrate without including s as the upper bound. Any help will be appreciated
  19. W

    Integrating exp(x^2): Solution & Explanation

    Hello everyone, This is my first post on the forum; I'm pretty sure my question fits in this section. I am having a lot of difficulty finding the definite integral \int^{+\infty}_{-\infty}e^{-2ax^{2}} dx where a is positive and real. I know the answer is [tex]\\sqrt{\frac{\pi}{2a}}, but...
  20. D

    Integrating 1/xln(x) using integration by parts

    Homework Statement Integrating 1/xlnx by parts... Homework Equations Find the integral of 1/xlnx The question asks to solve by substitution, which I can do and results in ln(ln(x)) + c It then asks to compute using integration by parts, and then to explain how it can be true (because...
  21. Saladsamurai

    Why Do We Use Integrating Factors in Solving First Order Linear ODEs?

    Hello all! :smile: I through a section in my text (by https://www.amazon.com/dp/0133214311/?tag=pfamazon01-20) on 1st Order linear ODEs. I am understanding the derivation of the integrating factor method pretty well; however, there are some aspects of the mathematics that I am getting hung up...
  22. C

    After brakes are applied how far does the car travel? - integrating twice

    Homework Statement t seconds after the brakes of a car are put on, the acceleration of the car is a(t) = -6t - 4 ft/sec^2. If the automobile was moving at the speed of 32 ft/sec when the brakes were put on, how far does it go before stopping? Homework Equations a(t) = -6t - 4 ft/sec^2...
  23. M

    Can the arc length be calculated using polar coordinates?

    It seems to me that integrating a polar equation should give you the arc length of the curve, rather than the area under it. This is my reasoning: A polar equation is in the form of: (1) r = f(\theta) The arc length of a segment of a circle where the radius is constant is given...
  24. U

    Integrating to find velocity and position equations

    Homework Statement The acceleration of a certain particle is a function of time: a(t) = pt2-qt3, where p and q are constants. Initially, the velocity and position of the particle are zero. (a) What is the velocity as a function of time? (b) What is the position as a function of time? The...
  25. E

    Caculus Help : Integrating with trig identities?

    Homework Statement integrate: sin (2x)/(1+sinx) Homework Equations (sin x)^2 + (cos x) ^2 = 1 sin (2x) = 2 sin x cos x cos (2x) = (cos x)^2 - (sin x)^2 The Attempt at a Solution I've been trying to integrate this thing for about an hour by rearranging various trig...
  26. S

    How Do You Integrate (2x^2+1)/x?

    Homework Statement I haven't done much math for years. just a little reminder would be very appreciated. when you take integral for (2x^2+1)/x dx I believe this can break down into integral 2x dx + integral 1/x dx What I wondered about was is this summation of those two as...
  27. B

    How Does Integrating Modified Newton's Law Lead to the Velocity Formula V(t)?

    Homework Statement Starting from the modified Newton's Law (dp(rel))/dt=F with a constant Force F, and assuming that the particle starts with v=0 at time t=0, show that the velocity at time t is given by V(t)=c [(Ft/mc)/(1+ Ft/mc)] Homework Equations The Attempt at a...
  28. G

    Integrating a two variable equation

    Homework Statement This is the problem I was given: I_{n} = \int^{0}_{\infty}(1 + x^{2})^{-n} dx I was told to "deduce that" I_{n} = 2n(I_{n} - I_{n + 1}) so I can "Hence or otherwise show that" \int^{0}_{\infty}(1 + x^{2})^{-4} dx = \frac{5\pi}{32} Homework Equations I...
  29. B

    How Do You Integrate sin(2x) e^(sin x)?

    hey guys I am absolutely stumped on this one integration problem: it asks us to integrate sin (2x) e ^ (sin x) i integrated by parts once and was left with an even larger term to integrate, which leads me to believe that i might be doing it wrong any help is appreciated, thanks
  30. jegues

    Can You Evaluate the Cross Product in Vector Integral Calculations?

    Homework Statement See figure Homework Equations The Attempt at a Solution For an integral like this am I allowed to evaluate the cross product between the to vectors, \vec{u} and \vec{v}? If so then, \vec{p} = \vec{u}\times\vec{v} and, \int f\vec{p} = -3\int...
  31. T

    How Do You Integrate 1/(1+a*cos(x))?

    Homework Statement How to integral this one? 1/(1+a*cosx) Homework Equations The Attempt at a Solution
  32. N

    The volume of a spherical cap by integrating and using Cartesian coordinates

    Dear all, How can I derive the volume of a spherical cap by integration and using the Cartesian coordinate system. The sphere is located at the (0,0,0) coordinates and its radius is set to r. The height of the cap is also set to (r-h). I googled a lot but I couldn't find it. I would...
  33. J

    How to Correctly Integrate Polar Coordinates Example?

    Homework Statement I was looking at the book's example. The author left the final integration as an exercise, and I was attempting it. 1/2 integral of [ (2 - 2sin(delta) )^2 - 0 ] d delta from 0 to 2pi for the sake of work, i will let x = delta (2-2sin(x))^2 => 4 - 8sinx + 4sin^2(x) and i...
  34. A

    Integrating an accelerating Worldline

    Geometrically: Is it correct of think that a line integration in effect converts a curvilinear segment into an equivalent straight line?? If this is basically applicable then it would mean converting the accelerating worldline into a straght line in Minkowski space. My...
  35. D

    Integrating derivate of Dirac: Where is my fault?

    Hi, I want to do the following calculation: c_{m,n} = \int_{-\infty}^{\infty} t^m \phi(t-n)\,dt I know three things: I know the values of c_{m,n} for m={0,1} and the first 4 for m={2,3} I know that my \phi is symmetric, i.e. \phi(t) = \phi(-t) The Fourier transform of \phi(t)...
  36. S

    Integrating accelerometer data (obtain velocity and distance)

    Hi everyone! I'm trying to work with an accelerometer to measure distances (straight line) but I'm not being very successful.. I've made this experiment: attached the accelerometer to a electric slot car and accelerate it to the maximum until it reached the end of a straight line track...
  37. L

    First order nonlinear ODE - Integrating factor + exact differentials, or not?

    First order nonlinear ODE -- Integrating factor + exact differentials, or not? Hello everyone, (I apologize if this did not format properly, if not I will attempt to edit it if that functionality is available upon submitting a question). I recently came across the following nonlinear ODE...
  38. D

    Integrating over a bounded surface

    Homework Statement Find the average value of z for a the spherical surface of radius R that resides above the x-y plane. Homework Equations Equation of a sphere x^2+y^2+z^2 = R^2 The Attempt at a Solution I rearrange the equation above and do a double integral z_{total} = \int...
  39. G

    Integrating by parts in path integral (Zee)

    Hi all, I have an exceptionally basic question, taken from P21 of Zee. Eq. 14 is Z=\int D\psi e^{i\int d^4x(\frac{1}{2}[(\partial\psi )^2-m^2\psi^2] + J\psi)} The statement is then made that 'Integrating by parts under the \int d^4x' leads to Eq. 15: Z=\int D\psi e^{i\int...
  40. Y

    What is the step of integrating this?

    Homework Statement I need help in finding the answer of this integration: \int \frac{d^n [(x^2-1)^n]}{dx^n}dx I have no idea how to even start, please at least give me hints how to substitude. Thanks Alan
  41. M

    1st order linear differential eq. using integrating factor

    Homework Statement Solve the inital value problem for y(x); xy′ + 7y = 2x^3 with the initial condition: y(1) = 18. y(x) = ? Homework Equations dy/dx +P(x)y=Q(x), integrating factor=e^∫P(x) dx The Attempt at a Solution Multiplied all terms by 1/x to get it in correct form...
  42. R

    Understanding the Concept of Backwards Integration in Definite Integrals

    Hi I have a question, if I have a function that is continuous on the interval [a, b] where a <= b, why would integrating this interval backwards (i.e. taking the definite integral from b to a) be the negative of taking the definite integral from a to b? Can someone explain this from the...
  43. T

    Integrating for Fourier Series

    Homework Statement For positive integers m and n, calculate the two integrals: \frac{1}{L}\int^{L}_{-L}sin(\frac{n \pi x}{L})sin(\frac{m \pi x}{L})dx and \frac{1}{L}\int^{L}_{-L}sin(\frac{n \pi x}{L})cos(\frac{m \pi x}{L})dxHomework Equations \int u v' dx = [u v] - \int u' v dxThe Attempt at a...
  44. D

    Solve DE by finding an integrating factor (please check my work)

    Homework Statement Solve (x + 2) sin y dx + x cos y dy = 0 by finding an integrating factor .....M......N..... M_y (x+2)siny = (x+2)cosy N_x xcosy = cos y M_y not equal to N_x, therefore equation is not exact.. so far so good? thanks Homework Equations The Attempt at...
  45. D

    Verifying an integrating factor -please check my work , thanks.

    Verifying an integrating factor --please check my work , thanks. Homework Statement Verify that 1/y^4 is an integrating factor for (3x^2-y^2)dy/dx - 2xy = 0, and then use it to solve the equation (1/y^4)* (3x^2-y^2)dy/dx = 2xy* (1/y^4) =3x^2 / y^4 dy = 2x/y^3 dx =3x^2 / y dy = 2x...
  46. W

    Integrating over Region A: Calculating the Volume of a Cone

    Homework Statement Let A be the region that in space bounded by the balls: x^2 +y^2 + z^2 =1 , x^2 +y^2 +z^2 =4 , above the plane z=0 and inside the cone z^2 = x^2 +y^2 . A. Write the integral \int \int \int_{A} f(x,y,z) dxdydz in the form: \int \int_{E} (\int_{g^1(x,y)}^{g^2(x,y)}...
  47. N

    Integrating a Kronecker Delta with F(u) and G(v)

    Hi alll, I have an integral which includes a Kronecker delta: I = \int_{u=0}^{a} \int_{v=0}^{a} F(u) G(v) \delta_{u,v} \, \mathrm{d}u \, \mathrm{d}v I know that for a 1D integral there exists the special property: \int F(u) DiracDelta(u-a) = F(a) However, is there something equivalent for...
  48. S

    Integrating an absolute function

    Homework Statement 1 ⌠ | 10^(1/2)*(x^5)+(5*x^(1/5)) | dx ⌡ −1 Homework Equations once the absolute value is gone you can just integrate the function The Attempt at a Solution how do you get rid of the absolute, and how do you then integrate it, do you use the product rule...
  49. Mentallic

    Integrating Double Integrals: A Calculus 1 Challenge

    Homework Statement find \int\int_D sin\left(\frac{y}{x}\right)dA bounded by x=0, y=\pi, x=y^2The Attempt at a Solution I've only studied calculus 1, this problem is for my friend. I did read up briefly on double integrals however and this is why I'm stuck: From the limits and where the graphs...
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