Arc length Definition and 286 Threads

Arc length is the distance between two points along a section of a curve.
Determining the length of an irregular arc segment is also called rectification of a curve. The advent of infinitesimal calculus led to a general formula that provides closed-form solutions in some cases.

View More On Wikipedia.org
  1. Z

    Find the Arc Length of a Curved Line

    Homework Statement find the arc length x=2e^t, y=e^-t, z=2t Homework Equations The Attempt at a Solution dr/dt=2e^ti-e^-tj+2 ds/dt=sqrt((4e^2t)+(e^-2t)+4)) dt =integral from 0 to 1 sqrt(4e^4t+4e^2t+1)/e^t sorry about the lack of latex, I have no idea how to integrate this function
  2. T

    What is the Conversion Factor for Nautical Miles to Statute Miles?

    Homework Statement Given: The diameter of the Earth is 8000 miles If angle ACB has measure 1', then the distance between A and B is a nautical mile. Approximate the number of and (statute) miles in a nautical mile. Homework Equations Arc Length Therom: s=r(theta) The...
  3. S

    Finding Arc Length of x & y from 0 to 4

    Homework Statement Find the length of \ x =t^{3} \ y =t^{2} 0 \leqt\leq 4 Homework Equations I would write the formula for the arc length but I don't know how to make a definite integral. The Attempt at a Solution I have the whole thing set up and I'm ready to integrate but I...
  4. B

    Find the arc length of a curve over an interval

    Homework Statement I'm trying to find the arc length of a curve over an interval and I've arrived at \int (y4 +2y2 +1)1/2 dy and now I'm pretty sure i should use a u substitution in order to integrate. I tried using u=y2 so du=2y dy so dy=du/2y Then you have \int (u2+2u+1)1/2 and...
  5. Battlemage!

    Basic Calculus III- Arc Length Parameter and Length- Getting a negative length

    Homework Statement Find the Arc Length Parameter along the curve from the point where t = 0 by evaluating the integral: s = ∫ |v(τ)| dτ from 0 to t Then find the length of the indicated portion of the curve. Homework Equations The vector I am using for this: r(t) = (etcos t)i + (etsin...
  6. W

    Find the arc length for the given interval (parametric curve)

    Find the arc length. x = sqrt(t) y = 6t - 2 Interval from 0 to 5 inclusive. Whenever I do this, I get a long answer with big numbers in the numerator all divided by 48. Can someone walk me through the steps? THanks.
  7. James889

    Trying to calculate arc length

    Hi, Im trying to calculate the arc length of the function f(x)=x\sqrt{x} From x=1 to x=7 But I am getting the wrong answer and I am not sure why. The formula is \int^{7}_{1}\sqrt{f'(x) + 1} The derivative of f(x) =\frac{x}{2\sqrt{x}} + \sqrt{x} Squaring yields ~~\frac{x}{4} + 2x +1 which...
  8. C

    Arc length for these parametric equations

    Homework Statement Find the arc length of the curve described by the parametric equations: x=2e^t & y=3e^3t/2 ln3≤t≤2ln3 Homework Equations S = ∫(a->b) √[(dy/dt)^2 + (dx/dt)^2]dt The Attempt at a Solution Differentiated the two parametrics: dy/dt = 2e^t dx/dt = (3/2)*3e^3t/2 =...
  9. B

    Does zero arc length mediation of EM cause the wavefunction

    The path taken by a ray of light, from an event E1 to event E2, follows a zero arc length curve such that E2 ∫ds = 0 1. E1 Where S is the interval along the null geodesic path between the...
  10. M

    Arc Length 3-D: Find Length Between (8,4,0) & (24,36,4log(3))

    Homework Statement Consider the path f{r}(t) = (8t, 4t^2, 4log(t) ) defined for t > 0. Find the length of the curve between the points (8, 4, 0) and (24, 36, 4log(3)). Homework Equations \int|r' (t)|dt The Attempt at a Solution r(t)=(8t, 4t^2, 4log(t)) r'(t)=(8, 8t, 4/(ln(10)t)) |r'...
  11. L

    Help with Arc Length Problem: Evaluating Integral from x=8 to x=27

    Homework Statement Hello, I have an arc length problem that I’m stuck on, and I would really appreciate it if someone could help me out. I understand the arc length formula and everything, it’s evaluating the integral produced by it. The author in the book I got this problem from tells the...
  12. R

    Arc Length & Parametric Curves

    Homework Statement Find the length of the curve y=x^2-4|x|-x from x=-4 to x=4. The Attempt at a Solution I realized there is a corner at x=0 so i tried to get around this by pluggin in x for x>=0 and -x for x<0. However, my integrals don't match the answer...
  13. G

    Solve Arc Length Problem: Find Circumference of Wing Section

    Homework Statement I'm trying to compute the circumference of a wing section. I have broken up the airfoil circumference into arc pieces and used cubic splines to come up with an equation for each piece. For example, the arc nearest the leading edge of the wing is the function: y =...
  14. T

    What is the arc length of a falling prey described by a parabolic trajectory?

    Homework Statement A hawk flying at 2 m/s at an altitude of 80 m accidentally drops its prey. The parabolic trajectory of the falling prey is described by the equation below until it hits the ground, where y is its height above the ground and x is its horizontal distance traveled in meters...
  15. I

    Why Does the Line Integral of a Square Path's Perimeter Equal Zero?

    When I take the line integral around a square shape path "C" as follows: From A to B to C to D to A C1 = A(0, 0) to B (4, 0) t i 0 <= t <= 4 C2 = B (4, 0) to C (4, 7) 4 i + (t - 4) j 4 <= t <= 11 C3 = C (4, 7) to D (0, 7) (15 - t) i + 7 j 11 <= t <= 15 C4 = D (0, 7)...
  16. F

    How Do You Compute Arc Length and Surface Area for the Exponential Curve e^x?

    C: y=f(x)=e^x, where x is all real numbers. Compute the arc-length function S for C relative to C's y-intercept Computer the area S for the surface generated by revolving the curve C*:y=f(x)=e&x, where x is [0,a] and a is a positive constant, about the x-axis I've been trying this problem for 2...
  17. H

    Solving Arc Length Integral for y=ln(1-x^2) - 0 to 1/2

    Homework Statement ok, the original prob is : find the length of the curve of y=ln(1-x^2) x between 0, 1/2. Homework Equations The Attempt at a Solution ive made it this far: my integral is -1 + 2/1-x^2.....ok so i decompose the second part but in doing so i get a...
  18. G

    Evaluation of a (parabolic) line integral with respect to arc length

    Homework Statement Evaluate the line integral \[ \int_c yz\,ds.\] where C is a parabola with z=y^2 , x=1 for 0<=y<=2Homework Equations A hint was given by the teacher to substitute p=t^2 , dp=(2t)dt and use integration by parts. I also know from other line integrals with respect to arc length...
  19. S

    Calculating Arc Length for Parametric Equations with Simple Integration

    Homework Statement x = 1+3t^2 y=3+2t^3 0<= x <=4 Homework Equations L = integral from a to b of \sqrt{[dx/dt]^2 + [dy/dt]^2} dx The Attempt at a Solution dx/dt = 6t dy/dt = 6t^2 L = integral from 0 to 4 of \sqrt{(6t)^2 +(6t^2)^2} dx = " \sqrt{36t^2 +36t^4} dx = "...
  20. J

    Is Acceleration a Scalar Multiple of Arc Length?

    Homework Statement Show that d^2 R / dt^2 is NOT a scalar which is a multiple of d^2 R / ds^2 where R is a vector, s is arc length Homework Equations and The Attempt at a Solution I was thinking maybe it has something to do with the fact k = |d^2 R / ds^2| a = d^2 R / dt^2 = d|v|/dt * T + k...
  21. N

    Calculating Arc Length of y=x^2 from 0 to 10 using Trig Substitution"

    Homework Statement Find the arclength of the function y=x^2 when x is between 0 and 10. Homework Equations Arclength here is \int_{0}^{10} \sqrt{1+(2x)^2} dx (It's intended to be the integral from 0 to 10 of the quare root of 1+(2x)^2. My latex skills suck.) The Attempt at a...
  22. V

    Arc Length of y^2=4(x+4)^3 from x=0 to x=2

    Homework Statement Find the arc length of the equation y^2=4(x+4)^3 from x=0 to x=2 Homework Equations L=\int_{a}^{b}\sqrt{1+f'(x)}dx The Attempt at a Solution L=\int_{0}^{2}\sqrt{1+9(x+4)}dx which simplifies in to L=\int_{0}^{2}\sqrt{9x+37}dx and I'm stuck there--how should i try...
  23. C

    Arc length and straight lines(Need clarification please)

    Homework Statement Here is difficult one guys, Lets imagine that an object movement along a curve is described by the parameterized function called \omega: I \rightarrow \mathbb{R}^3 which moves on the interval [a,b]\subset I. and this depended on motor which supplies the constant...
  24. G

    Arc length (mostly a problem with integration)

    Homework Statement Find the arc length oh the graph f(x)=cosx on the integral [0,\frac{\pi}{2}] Homework Equations \int^{b}_{a}\sqrt{1+{f'(x)}^{2}}dx The Attempt at a Solution Alright so I took the derivative of f(x) to get f'(x)=-sinx then I squared it to get sin^{2}x so I could...
  25. L

    How Can I Calculate Arc Length Without a Calculator?

    How in gods name do I do that? I attempted that integral and... it just can't be integrated! What I tried: That doesn't help one bit... How do I do this? NOTE: No graphing calculator is to be used.
  26. B

    What is the Arc Length of y=\sqrt{x} from x=0 to x=2?

    Homework Statement Find the arc length of y=\sqrt{x} from x=0 to x=2. The Attempt at a Solution I don't know, this is a nastier integral than it looks. From the substitutions, s = \int_0^2 \sqrt{1 + \frac{1}{4x}} dx. From doing this over and over again I already know the answer will have...
  27. P

    Arc Length in Parametric equation

    I know this is very simple, but the end integral just kills me Homework Statement Given equation in Parametric form x=\sqrt{2t+1}), y=6t Find arc length Homework Equations The Attempt at a Solution take x' & y' then Take integral of \int\sqrt{1/(2t+1) + 36} This is where I got stuck ...is...
  28. K

    Arc Length of y = (2/3) * (x^2-1) ^ (3/2): Solve It

    Homework Statement y = (2/3) * (x^2 - 1) ^ (3/2) 1 <= x <= 3 Length = ?Homework Equations L = \int\sqrt{1 + (dy/dx)^2} dxThe Attempt at a Solution dy/dx y = (2/3) * (x^2 - 1) ^ (3/2) = 2x * sqrt(x - 1) Any ideas for a proper substitution? The answer on wolfram seems ridiculous. :bugeye:
  29. N

    Line integral - finding the arc length

    a curve is given as 3 parameters of t: x=a(3t - t^3), y=3a(t^2), z=a(3t + t^3) i have to find the arc length measured from origin and curvature as functions of t. would i be correct in using the integral at the bottom of page 2 here: http://homepages.ius.edu/wclang/m311/fall2005/notes17.2.pdf
  30. J

    Calculating Arc Length in Polar Coordinates

    Homework Statement Find The length of r=sin³(x/3) 0<x<3pi/2 2. The attempt at a solution well first i found r'=3.cos(x/3).1/3.sin²(x/3)=cos(x/3)sin²(x/3) r²=cos²(x/3)sin^4(x/3) then i put the formula integral of radical (r'²+r²)dx and I'm stuck here any help?
  31. R

    Finding Arc Length of f(x) = (4-x^2)^(1/2)

    Homework Statement What is the arc length of f(x) = (4-x^2)^(1/2)? Homework Equations The Attempt at a Solution
  32. D

    How to Calculate Arc Length for Parametric Curves in 3D Space?

    Homework Statement x = \frac{u^{2} + v^{2}}{2} y = uv z = z Find the arc length given: u(t) = cos(t), v(t) = sin(t), z = \frac{2t^{\frac{3}{2}}}{3} Homework Equations ds^{2} = dx^{2} + dy^{2} + dz^{2} In curvilinear coordinates thhis becomes ds =...
  33. D

    Calculate Arc Length of Hypocycloid Function | Homework Help

    Homework Statement Find the arc length of r(t) = cos(t)^3 i + sin(t)^3 j from t = 0 to t = 2 * Pi It's a hypocycloid that's four cusped. Homework Equations s = \int\sqrt{x'^2 + y'^2} The Attempt at a Solution x = cos(t)^3 y = sin(t)^3 x' = -3cos(t)^2*sin(t) y' =...
  34. T

    Arc length of a curve (trigonometric identity)

    Homework Statement find arc length of the segment of the 2space curbe that is defined by the parametric equations x(t) = t-sin(t) y(t) = 1+cos(t) 0 ≤ t ≤ 4π The Attempt at a Solution I've found dx/dt and dy/dt respectively and put them into the arc length equation, i.e...
  35. J

    How do I integrate sqrt(t^2 + 8)?

    I am trying to figure out the following arc length problem, and it's really coming down to a question over intregration. Compute the length of the curve r(t)=(4t)i +(4t)j+(t^2+6k) over the interval 0 to 6. I have dr/dt = (4, 4, 2t) , and then used the arc length equation: L= integral...
  36. M

    Arc length in polar form θ = f (r)

    hi! i need some help here, do you have any available example on how to find the arc length in polar form θ = f (r)? using integral calculus, i mean. i searched the internet but i only got the r= f(θ) example. i hope you can help me. thanks!:)
  37. L

    Arc length and angle between two cities

    Two cities on the surface of the Earth are represented by position vectors that connect the location of each city to the centre of the earth. Assuming that the centre of the Earth is assigned the coordinates of the origin, and that the Earth is a perfect sphere, outline the steps that would lead...
  38. R

    Understanding Arc Length and Line Integrals for Surface Area Calculation

    Hello, I am trying to solve for the surface area of a odd surface for a fire relief PSV and needed to do a line integral but I was reading into my calculus book and going back to the definition of arc length I am confused: L = lim_{n\rightarrow\infty}\sum (P_{i-1}*P_{i}) Multiplication should...
  39. S

    How do I solve for arc length?

    How do I solve this ?
  40. L

    Arc length/ surface area with integrals

    I have a question on the formulas for arc length and surface area. Do you use the formula: s= \int_{c}^{d}\sqrt{1+[g'(y)]^2}dy only when you are provided with a function x=g(y)?? Can you convert that to y=g(x) and solve it by replacing g'(y) with y(x), changing the bounds and the dy to dx...
  41. M

    Definition of arc length on manifolds without parametrization

    Curves are functions from an interval of the real numbers to a differentiable manifold. Given a metric on the manifold, arc length is a property of the image of the curves, not of the curves itself. In other word, it is independent of the parametrization of the curve. In the case of the...
  42. Peeter

    Newie relativity question: proper time vs. arc length?

    Doran/Lasenby define a proper interval as: \delta \tau = \int \sqrt{\frac{dx}{d\lambda} \cdot \frac{dx}{d\lambda}} d\lambda (c=1, x= (t,x1,x2,x3) is a spacetime event, and the dot product has a +,-,-,- signature) and say that this is called the proper time. I can see that this...
  43. Z

    Arc Length Need Verification, If Wrong, Can You Help?

    Homework Statement Length of curve: y=1/2(ex-e-x) from 0 to 2 Homework Equations s = ∫√[1+(dy/dx)^2] dx The Attempt at a Solution [sqrt(4+2e^(-x)+e^x)]*[-1+e^x]/[1+e^x]. = 3.323971
  44. H

    Simplifying a arc length problem

    Simplifying an arc length problem I have L= Int(-2..2) sqrt(16*cosh(4*t)^2+9*sinh(4*t)^2+9) and can use Maple to simplify this to sqrt(25*cosh(4*t)^2) but I just can't see how that is done. (or how to get maple to show me the steps!) Can anyone help by showing the steps, including any...
  45. J

    Why Does Changing Integration Limits Affect Arc Length Calculation?

    Homework Statement Find the length pf the curve over the given interval. r=1+\sin\theta 0\preceq\theta\preceq\2\pi The Attempt at a Solution Ok I set it up as: 2\pi \int\sqrt((1+\sin\theta)^2+cos^2\theta) 0 and by simplifying and integrating, I get...
  46. D

    Calculating Polar Arc Length for r=1/theta from 2 Pi to Infinity | Homework Help

    Homework Statement Find the length of the spiral of r=1/theta for theta\geq2 \pi Homework Equations \int\sqrt{r^{2}+r'^{2}} The Attempt at a Solution I thought of the formula for polar arc length, which is the integral of the square root of the sum of the square of r and the square...
  47. M

    What I am doing wrong? arc length of parametric functions

    So this seems to be a pretty straightforward question but I keep getting the arc length to be 0 and I redid this question many times.. Find the length of the parametrized curve given by x(t) =t^{2}-8t + 24 y(t) =t^{2}-8t -7 How many units of distance are covered by the point P(t)...
  48. R

    Arc length of vector-valued function; am I starting right?

    Homework Statement Given: R(t)= <(1/2)t^2, (4/3)t^(3/2), 2*sqrt(3)t> Find: Arc length function s(t) where t_0 =0 Homework Equations Is this the correct formula? ∫[0,t] sqrt( derivative^2 + derivative^2 +derivative^2) dt ∫[0,t] sqrt(t^2 + 4t + 12) dt The Attempt at a Solution...
  49. R

    Arc length help extended to surface area and centroid.

    Homework Statement A curce,C, has equation y=x^{\frac{1}{2}}-\frac{1}{3}x^{\frac{3}{2}}+\lambda where \lambda>0 and 0\leq x \leq 3 The length of C is denoted by s. Show that s=2\sqrt{3} The area of the surface generated when C is rotated through one revolution about the x-axis is denoted...
Back
Top