Parametric Definition and 650 Threads

  1. J

    Parametric Representations of Circles and Ellipses

    Sketch and represent parametrically the following: (a) \mid z+a+\iota b\mid =r \ \mbox { clockwise}\\ , (b) ellipse 4(x-1)^2 + 9(y+2)^2 =36 \ . Taking (a) first \mid z + a + \iota b \mid = r \mbox{- is the distance between the complex numbers }\ z=x+\iota y \ \mbox{ and } \ a + \iota b \...
  2. L

    Parametric equation of a line and a plane

    I CAN'T SEEM TO GET THE ANSWER THAT IS CONSISTENT WITH MY UNDERSTANDING OF THE USE OF DOT AND CROSS PRODUCTS AND THE USE OF THE PARAMETRIC EQUATION OF THE LINE. LOOK AT THIS PLEASE: the parametric equation of the line is: x = 2 + 3t y = -4t z = 5 + t the plane is 4x + 5y - 2z = 18...
  3. A

    Parametric and cartesian equations? HELP

    parametric and cartesian equations?? HELP! 1. x = 3t, y = 9t^2, negative infinity<t<positive infinity 2. a) What are the initial and terminal points, if any? Find a Cartesian equation for a curve that contains the parametrized curve. What portion of the grap of the Cartesian equation...
  4. A

    Commutators and the Parametric Nonrelativistic Particle?

    OK, I'm a wee bit sleep deprived and cannot recollect some facts about the Dirac quantization of gauge theories. With the quantization of the parametrized nonrelativistics particle, do we still change the Poisson bracket into commutators? More specifically, for the non-relativistic particle...
  5. P

    How to Convert Parametric Equations into a Cartesian Equation in 3D Modelling?

    Okay, I was doing 3D modelling. To save space I used vector functions to render terrain. Anyway, I came up with 3 parametric equations - each a function of an axis: e.g.: x=4t, y=5t+6, z=7t-9. How can you convert this into a Cartesian Equation?:confused:
  6. A

    Finding A and L in Parametric Equation X(t)

    Homework Statement The equation X(t)=A+tL is the parametric equation of a line through the point P:(2,-3,1). The parameter t represents distance from point P, directed so that the I component of L is positive. We know that the line is orthogonal to the plane with the equation 4x-6y+5z=6...
  7. T

    Solve Parametric Particle Homework: Find Time, Speed at (3,1)

    Homework Statement Consider a particle along a curve C and whose position is given by the vector: s(t) = < sqrt(t2), t3 - 3t > Last part of the question: There is an unknown force that is keeping this particle on trajectory C. At what value of t must the force cease in order for the...
  8. B

    Find parametric question for the plane

    Homework Statement Give parametric questions for the plane : 2x-3y+z-6=0 The Attempt at a Solution i know that the normal is (2,-3,1) how do i find the direction vector of the plane?
  9. K

    Surfaces/Areas of Revolution - Parametric

    Suppose that you have a parametric curve given by x = f(t), y = g(t), a ≤ t ≤ b What will the Surface of revolution and Volume of revolution around the x-axis be? I have two candidates: Surface: S = 2*pi*int( |g(t)|*sqrt( (df(t)/dt)^2+(dg(t)/dt)^2 ) , t=a..b) Volume: V = pi*int(...
  10. A

    Parametric equations for geodesics

    What are you trying to do when you find parametric equations for a geodesic lines on a surface? Take the metric ds^2 = dq^2 + (sinh(q)*dp)^2 Are you simply trying to get q as a function of s? and p as a function of s? If so, why? Thanks
  11. S

    Determine the vector and parametric equations

    Determine the vector and parametric equations of the plane that contains point C(1,-2,6) and the z-axis I take this to mean that any point on the z-axis is valid so does that mean either (0, 0, 1) or (1, -2, 5) are also on the plane?
  12. J

    3-dimensional parametric equations

    3-dimensional parametric equations [Updated] Look lower for update... Homework Statement Well, my problem is that I need to give some examples on 3-dimensional parametric equations. So far I've found out what parametric equations are, and more specifically what 3-dimensional parametric...
  13. S

    Finding Parametric Equations for Tangent Line of Surface Intersection

    Homework Statement 5. Find parametric equations for the tangent line to the curve of intersection of the surfaces z^2 = x^2 + y^2 and x^2 + 2y^2 + z^2 = 66 at the point (3, 4, 5). The Attempt at a Solution f(x,y,z) = x^2 + y^2 - z^2 g(x,y,z) = x^2 + 2y^2 + z^2 Partial derivz...
  14. D

    Differentiating Parametric Functions

    Given: \begin{array}{l} x = 2\cos t \\ y = 2\sin t \\ \end{array} find \frac{{dy}}{{dx}} I started by finding dy/dt and dx/dt \begin{array}{l} \frac{{dy}}{{dt}} = 2\cos t \\ \frac{{dx}}{{dt}} = - 2\sin t \\ \end{array} Now, dy/dx = (dy/dt) / (dx/dt)...
  15. J

    Parametric equations for a helical pipe

    I am trying to represent a helical pipe in x,y,z co-ordinants, would the x and y co-ordinants simply be multiplied by the equation of a circle if the growth of the helix is in the z direction? Any help would be appreciated. Thanks
  16. M

    Area using Parametric Equations

    Homework Statement Notice the curve given by: f(t) = x = 36-t^2 g(t) = y = (t^3)-25*t The curve makes a loop which lies along the x-axis. What is the total area insde the loop. Homework Equations Integral from alpha to beta of g(t)*f'(t) dt The Attempt at a Solution Ok, so I...
  17. C

    Parametric coordinates of an ellipse

    Homework Statement \frac{x^2}{a^2}+\frac{y^2}{a^2(1-e^2)} =1 The ellipse meets the major axis at a point whose abscissa is \lambda. Find lim \theta ->0. Homework Equations Parametric coordinates of an ellipse: (acosx,bsinx) The Attempt at a Solution The abscissa is the x...
  18. L

    What Is the Significance of Parametric Equations in Mathematics?

    Hi, Can someone explain to me what a parametric equation is exactly? Why it is used (instead of a normal function)? In other words, what is the significance of it? Second, to be more specific, in my book, there is an example where r(t) 2 costi + 2sintj + tk t>0. Then what they say is...
  19. J

    Solve Parametric Eq: Semicircle Mean Value w/ Respect to Theta

    The semicircle \mbox{f(x) = }\sqrt{a^2-x^2} \mbox{ -a} <=\mbox{ x }<= \mbox{a }, ( see my last thread) has the parametric equations x= }a cos\theta\mbox{, y=} a sin\theta, 0 <= \theta <= \pi, show that the mean value with respect to \theta of the ordinates of the semicircle is 2a/\pi(.64a)...
  20. Q

    Intersection of two 3D parametric curves

    Hi, I have two parametric curves defined in three dimensions, which are functions of a variable t, like so: x1 = f1(t) y1 = f2(t) z1 = f3(t) x2 = f4(t) y2 = f5(t) z2 = f6(t) I am trying to find the intersection of these two curves, but I am having some difficulty with the...
  21. C

    Parametric Curves: Tangent Lines

    Homework Statement Find equations of the tangents to the curve x=3t^2+1, y=2t^3+1 that pass through the point (4,3). The Attempt at a Solution I was able to find the equation y=x-1 as a tangent line through the point (4,3) for the part of the curve above the x-axis since (4,3) is on...
  22. R

    Vertical tangents of parametric curves

    I learned that vertifcal tangents occur at a parametric curve if the derivative of the curve is undefined. That is given dy/dx = dy/dt / dx/dt, a vertical tangent occurs when dx/dt = 0. I don't understand why this is so. I know that vertical tangents occur when the slope is infinite, but...
  23. S

    Parametric curve and some irregular integtrals

    Homework Statement 1) Consider the paramerric curve given by x = t^2 + 3t and y = 4 - t^2 a) Find an equation of the tangent lne to the curve at the point (x,y) = (0,-5) b) Determine the equation of every vertical tangent line to this parametric curve. 2)For each of the following...
  24. K

    Derivation of parametric function

    I get the first derivative correct, but what's wrong with my attempt to find the second derivative? http://www.badongo.com/pic/421533
  25. E

    Parametric function or statistic?

    Which one would you say this is :confused: : E(|x1-x2|) x1, x2, xn - a sample of n values on the underlying random variable... I was thinking this is a statistic :frown:
  26. G

    How can I solve the parametric representation problem for x^3+y^3=u^3+v^3?

    Does anyone have any ideas on how to even start this problem? I am supposed to find a general solution in rational numbers for (aside from the trivial ones): x^3+y^3=u^3+v^3 Actually, I'm given the answer (which is really messy) and am supposed to show how to derive it. The book gives the...
  27. S

    What values determine the concavity of a parametric curve?

    Hello, My textbook says that to determine concavity we calculate the second derivative of the curve. This is a problem from my book, x = t^2 and y = t^3 - 3t the second derivative of this is (3(t^2+1))/(4t^3) I know all the steps to get to this point.. However, the book says that...
  28. L

    Parametric Equation (u,v,θ): Explained

    In coordinates (u,v,\theta): x = \sqrt{uv} \cos{\theta}, y=\sqrt{uv} \sin{\theta}, z = \frac{1}{2}(u-v) What does this represent?
  29. S

    How Do You Calculate the Concavity and Tangents for Parametric Equations?

    1 If x = t^{3} - 12t , y = t^{2} - 1 find \frac{dy}{dx} and \frac{d^{2}y}{dx^{2}} . For what values of t is the curve concave upward. So \frac{dy}{dx} = \frac{2t}{3t^{2}-12} and \frac{d^{2}y}{dx^{2}} = \frac{2}{3t^{2}-12} So 3t^{2}-12 > 0 and t > 2 for the curve to be concave...
  30. L

    LaTeX How to type Optimization of a Parametric equation, in LaTeX?

    Hi there I was just wondering how to type Optimatiozion of a Parametric equation, in LaTeX?
  31. L

    Parametric Equations of x^2-y^2=1

    given x^2-y^2=1 find the parametric equation... i have no clue where to start... it looks like a cirlce equation but i know that not right so what the hell?
  32. L

    Parametric and Cartesian Equations

    ok I am give a parametric equations of x= 4 cos t and y=5 sin t I know that i have to solve the x equation for t then stick it in the y equation but i getting stuck or not rembering some simple stuff i should be. I believe i get t= cos(inv) (x/4) and substiute it into t in y. if so...
  33. C

    Convert f(x) to parametric holding something constant

    Hi all, if I have a problem like: The path of a particle is described by y=4x^2, and it has a constant velocity of 5 m/s. How do I make a parametric equation out of this? I tried doing: r = xi + f(x)j r = ti + 4t^2j, but then v = \frac{dr}{dt} = i + 8tj, so |v|=\sqrt{1+64t^2}, and at, for...
  34. B

    How Do You Convert Parametric Equations to Algebraic Form?

    X1 T = 10T Y1 T = 100 + (.5 * -9.8T^2) X2 T = 100 - 12.3 T X2 T = 0 How do I put this into algebraic form? it seems easy but I just can't get it. Do you simply add the X and Y components? If so what do x and y each stand for?? Does it have something to do with sine and cosine? =/
  35. B

    Changing from parametric form to algebraic form

    X1 T = 10T Y1 T = 100 + (.5 * -9.8T^2) X2 T = 100 - 12.3 T Y2 T = 0 How do I put this into algebraic form? it seems easy but I just can't get it.
  36. T

    Convert to Parametric Equation of surface?

    Convert to Parametric Equation of surface? How would I go about converting 9x^2+4y^2+z^2 = 640 I tried just to solve for each variable but this doesn't seem rightfor example \sqrt{\frac{640-z^2-4y^2}{9}}=x \sqrt{\frac{640-z^2-9x^2}{4}}=y \sqrt{\frac{640-4y^2-9x^2}{1}}=z
  37. B

    Line Integrals - Cartesian and Parametric

    Hello Im working on some line integral problems at the moment. The first one is really only a check - I think I've worked it out... Compute the line integral of the vector field B(r) = x^2 e(sub 1) + y^2 e(sub 2) along a straight line from the origin to the point e(sub 1) + 2 e(sub 2) + 4...
  38. T

    Find parametric equation for wheel

    a wheel or radius r rolls along a horizontal straight line.Find parametric equations for path traced by point P on the circumference of the wheel somebody pls help. thanx
  39. G

    Converting Tricky Parametric Equations into a Single Function | Tips & Tricks

    I would like to convert these parametric equations into a single f(x,y) = 0 function. X(t) = t^2 + t + 1 Y(t) = t^2 - t +1 In fact, what stops me is the imaginary roots of the parametric polynomials. Is there a way to get around the seemingly impossible explicit solving of the...
  40. B

    Have i done this parametric differentiation right?

    y=t+cost x=t+sint dy/dt=1-sint dx/dt=1+cost dy/dx= (dy/dt).(dt/dx) = (1-sint).1/(1+cost) = (1-sint)/(1+cost) = 1-tant and how do i get from there to the second order differential?
  41. N

    Parametric Equations: Exploring the Power of Analytical Geometry

    I find parametric equations to be simply amazing. I was wondering if there is a website, or better yet a book that covers them in more detail? I found it incredible how we can describe circles, ellipses, lines and other analytical geometrical shapes by them...so I wanted to know how deep...
  42. B

    Parametric Surfaces: Integral of S = x^2 + y^2 + 2z^2 = 10

    I need to take a surface integral where S is x^2 + y^2 + 2z^2 = 10. I need help with the parametrization of the curve. Letting x=u and y=v makes the problem too complicated. Can you let x=cos(u), y=sin(u) and z=3/sqrt(2)?
  43. E

    Partial Derivative of a Parametric Equation

    Hi, I'm getting confused over a few points on the derivative of a parametric equation. Say we the world line of a particle are represented by coordinates x^i . We then parametrize this world line by the parameter t. x^i = f^i(t) . Now here is where I get confused. The partial...
  44. K

    Arc length and parametric function

    I'm having trouble with the following: The problem is to find the arc length of the following parametric function: x=(e^-t)(cos t), y=(e^-t)(sin t) from 0 to \pi I found that \frac{\partial y}{\partial t} = e^{-t}(\cos{t}-\sin{t}) , \frac{\partial x}{\partial t} =...
  45. L

    Simplify Parametric Equations: Learn How to Convert to Cartesian Form

    hi apologise if this is in the wrong forum :) my lecturer has told me that i need to be able to express parametric equations as a cartesian equation in my exam later this month. my mind boggles ! here is an example i have found. Express the parametric equations x = 2 t - 2 and y = 3 t -...
  46. U

    Parametric equations for a line

    considering the surface 25x^2+25y^2+4z^2=54 The parametric equation for a line going thought point P=(1,1,1) is x=1+50t y=1+50t z=1+8t A plane an equation for the tangent plane through P. Here's what I know: the equation for a plane needs a perpendicular vector to the plane and a...
  47. M

    Equation for Point P's Path in Parametric Problem

    Circle A is fixed at center (1,0) with a radius 1. Circle B, also with radius 1, rotates at one revolution per (2*PI) seconds. Circle B is always connected to circle A at a single point. If at t=0, circle B is centered at (3,0) and point P (point p is on the edge of circle B) is at (4,0), what...
  48. J

    What is the Parametric Expression for the Lemniscate of Bernoulli?

    The lemniscate of Bernoulli is the curve that is the locus of points the product of whose distances from two fixed centres (called the foci) a distance of 2c apart is the cosntant [c^2. If the foci have Cartesian coordinates (\pmc, 0) the Cartesian equation of the lemniscate is ([x-c]^2 +...
  49. M

    Parametric Curves: Solving & Approximating

    1. I am given a curve defined parametrically by x= 2/t , y=1-2t i have found the equation of tangent at t=-2 to be y=4x+9, they have asked whether it cuts the curve again. how do i find that, since i don't know the original equation of the curve and can't solve them simultaneously. 2. Also...
  50. F

    Solving Parametric Equations for a Torus: Normal & Surface Areas

    Could someone please give me a clue how to solve these parametric equations or a starting position. torus specified by these equations x=(R+rcosΦ)cosθ y=(R+rcosΦ)sinθ z=rsinΦ calculate the normal to the torus N(θ,Φ) and entire surface area p.s anyone recommend a book or a...
Back
Top