Inverse Definition and 1000 Threads

  1. V

    Why Does This Inverse Trigonometry Problem Have Four Solutions?

    Homework Statement tan-1[2x/(1-x2)]+cot-1[(1-x2)/2x]=2π/3 2. The attempt at a solution tan-1[2x/(1-x2)]+cot-1[(1-x2)/2x]=2π/3 tan-1[2x/(1-x2)]=2π/6 take tan on both sides 2x/(1-x2) =sqrt(3) quadratic equation so it should have 2 solutions(sqrt(3) and sqrt(1/3)).But this question...
  2. J

    Inverse Trig Graphs: Domain and Range

    Hey everyone. Sorry to post another topic, but i thought this would be easy to find on google, to help me with , but i can't find it. All I am really lookin for is someone to let me know if my answers are right, and if not, then how i can fix them :) Anyways, i was asked to graph...
  3. C

    Challenge question to the community - - Determine the inverse function of

    f(x) \ = \ \dfrac{1 - \sqrt{x}}{1 + \sqrt{x}}Edit: \ \ I \ sent \ a \ PM \ to \ a \ mentor.
  4. J

    IVP Laplace Transform Problem - Tricky Inverse Laplace Transform

    IVP Laplace Transform Problem -- Tricky Inverse Laplace Transform Homework Statement Solve x"+x'+x=1, given x(0)=x'(0)=0 Homework Equations The Attempt at a Solution Plugged in transforms: s2*Y(s)-s*y(0)-y'(0)+s*Y(s)-y(0)+Y(s)=1/s Plugged in initial value points, simplified...
  5. S

    Strategies for Solving Inverse Laplace Transform Problems with Complex Roots

    Homework Statement Hello all, Having difficulty with this one question that involves complex roots. Here it is: F(s)=\frac{s+3}{s^3+3s^2+6s+4} I tried two different ways to tackle it. First method I divided it right away: F(s)=\frac{s+3}{s^3+3s^2+6s+4}\rightarrow{s^2+6-\frac{14}{s+3}} Is there...
  6. R

    Why is the distance squared in Newton's and Coulomb's inverse square laws?

    Why are Newtons law of universal gravitation, F=G\frac{m_{1}m_{2}}{r^{2}} and Coulombs law, F = K_{e}\frac{q_{1}q_{2}}{r^{2}} inverse square laws? I understand why they are inverse because the force decreases with distance but why is the distance, r, squared? Thanks AL
  7. E

    Inverse of an operator does not exist, can't see why

    I feel kind of lame, but here's my situation: We start with the operator g_{\mu \nu} \Box - \partial_{\mu}\partial_{\nu} and convert to momentum space to get -g_{\mu \nu} k^{2} - k_{\mu}k_{\nu}. Apparently it's easy to see that this has no inverse? I'm told that if it *did* it would be...
  8. T

    Question about Proof of Inverse Function

    I am reading the proof of the Inverse Function Theorem in baby Rudin and I have a question about it. How does associating a function phi(x) (equation 48) with each point y tell us anything about if f(x) is one-to-one? I'll show the proof below. Also, if f'(a) = A, and f(x)=x2, what would A-1 be?
  9. C

    Inverse Trig Function: Find Derivative of the Function

    Homework Statement find the derivative of the function f(x)=arcsec(4x) Homework Equations I think this is a Relevant equations. d/dx[arcsecu]=u'/(|u|(√u2-1) The Attempt at a Solution f'(x)=4/(|4|(√42-1) =1/√15 I keep getting wrong in my online homework why? :confused:
  10. C

    Inverse Trigonometric Problem Solve equation for x

    Homework Statement arctan(8x-8)=-1 Homework Equations I'm sure what this part wants. The Attempt at a Solution tan[arctan(8x-8)]=tan(-1) 8x-8=tan(-1) x=(1/8)(tan(-1)+8) x=(1/8)(-(tan(1)+8) x= I am stuck on the last part since the homework says Simplify the above equation...
  11. S

    Derivative of the inverse of sin(1/x)

    Homework Statement Find the derivative of the compositional inverse of f(x) = sin(1/x) restricted to (1,∞). You may use without proof that sin(x) is differentiable with derivative cos(x). Homework Equations (f^{-1})'(y_0) = \frac{1}{f'(f^{-1}(y_0))} The Attempt at a Solution...
  12. J

    Find the inverse of the polynomial.

    Homework Statement Find (f^{-1})'(a) of: f(x)=\sqrt{x^{3}+x^{2}+x+22} ; a=5. Homework Equations (f^{-1})'(a)=\frac{1}{f'((f^{-1})(a))} The Attempt at a Solution Well, I know to find an inverse: I need to set the equation equal to y, solve for x, then swap x and y. But I don't...
  13. F

    Domain & Range of Inverse Function f-1: x≤0, y≤0

    Homework Statement The function f:x→ 4-x2 for the domain x≤0. Find the inverse of is denoted by f-1 and state the domain and range of f-1. Homework Equations Set equation to 0 and solve for x to find inverse. The D and R is going to be switched for the inverse..? The Attempt at a...
  14. S

    Inverse Fourier Transformation of a Fourier Transformation

    I am having problem with the inverse transformation of a Fourier transformed function which should give the function itself. Let f=f(x) and let f be Fourier transformable (whatever that implies) Let \tilde{f}(k)=∫^{\infty}_{-\infty}dx e^{-ikx}f(x) (1) then we should have...
  15. T

    Inverse Fourier Transform using complex variables

    Homework Statement For α > 0, determine u(x) by the inverse Fourier transform u(x) = \frac{1}{2\pi}\int_{-\infty}^{\infty}\ \frac{e^{ikx}}{ik+\alpha}\ dk Homework Equations The Attempt at a Solution This seemed like a relatively simple residue problem. You just note that...
  16. D

    Integration of inverse trigonometric functions

    Homework Statement [SIZE="7"]∫ (x+2)dx/√(4x-x2) Homework Equations why was the -2 in -2(x-2) was ignored? The Attempt at a Solution so first i let u= 4x-x2 then, du=4-2x = -2(x-2) so to get (x+2) i equate it to (x-2)+4 so ... [SIZE="7"]∫ (x+2)dx/√(4x-x2) =...
  17. R

    What is the correct method for calculating the co factor of a 3 x 3 matrix?

    This is insane, I am trying to revise the inverse of matrices and this one element is being really stubborn, please help. Here is the matrix 3 -1 7 2 0 1 5 -2 6 I have transposed it 3 2 5 -1 0 -2 7 1 6 Now as for replacing the element of...
  18. C

    What are the Inverses of y=x^{2}+4x-6?

    Homework Statement The function y=x^{2}+4x-6 has two inverses. What are they and which domains lead to these inverses? Homework Equations The Attempt at a Solution y=x^{2}+4x-6 x=y^{2}+4y-6 y(y+4)=x+6 Not really sure where to go from here.
  19. A

    What is the Inverse Fourier Transform of (3jw+9)/((jw)^2+6jw+8)?

    Homework Statement (part of a problem) Find the inverse Fourier of F(w) = (3jw+9)/((jw)^2+6jw+8) where w is the angular frequency, w=2pi * f = 2*pi/T Homework Equations The fourier transfrom and its properties i guess. Also the exponential FT common pair exp(-at)u(t) <-> 1/(jw+a) where...
  20. A

    What's the inverse Laplace transform of this?

    Homework Statement L^{-1}\{\frac{1}{(s^2+4)^2}\} Homework Equations The Attempt at a Solution I have no idea how to solve this. Any idea to being solving the problem would be appreciated.
  21. T

    Solve Inverse Trig Function with Domain [-π/2, π/2] | Step-by-Step Guide

    Homework Statement My problem is as follows: find the inverse of 3x+1+\sin(x) with the domain [-\frac{\pi}{2},\frac{\pi}{2}] Homework Equations The Attempt at a Solution for this would I just try to solve as normal by setting y=f(x) then using the fact that \arcsin(x) = y or is...
  22. C

    Solving Sinusoidal Equations involving Cosine Inverse

    Suppose that a spaceship is fired into orbit from Cae Canerveral. Ten minutes after it leaves Cape, it reaches its farthest distance north of the equator, 4000 kilometers. Half a cycle later it reaches its farthest distance south of the equator (on the other side of the Earth, of course!), also...
  23. T

    Inverse of a logarithmic function

    Homework Statement Greetings everyone! I am having problems getting started with this question, which asks: Find the inverse of y = \frac{3-4e^x}{6-10e^x} Homework Equations The Attempt at a Solution I'm usually pretty good with these kinds of problems, but for some reason I seem to be...
  24. C

    Inverse Laplacetransform, can't find fitting formula

    Homework Statement Inverse Laplacetransform (3s+7)/(s^2+2s-2) Homework Equations (3s+7)/(s^2+2s-2) The Attempt at a Solution Split into 3s/(s^2+2s-2) and 7/(s^2+2s-2). I can't find a fitting transformpair(I use tables/formulas).
  25. G

    RLC inverse Laplace transform question

    The link below shows a circuit and the s-domain equation for I1(s) that I have derived; My question is on the portion of the equation containing the "(s+a)" terms. I am trying to arrive at the time-domain equation for I1(s) but instead of arriving at the Laplace transform pair shown in the...
  26. A

    Inverse linear algebra problem for stereo triangulation

    Hello everyone, I have been using the well-known Cal Tech camera calibration toolbox built by Jean-Yves Bouguet for stereo triangulation. Part of the toolbox's utility is that it's able to give 3D world coordinates from 2D coordinates in stereo image pairs, given a set of camera...
  27. G

    Inverse coefficients of dt & dr in Schwarzschild

    Awhile back A.T. & PeterDonis helped me through several basic confusions on my way to an intuitive understanding of geodesics in curved spacetime. I looked at http://www.relativitet.se/spacetime1.html http://www.adamtoons.de/physics/gravitation.swf...
  28. H

    Finding the Inverse Laplace Transform for Solving Fractional Equations

    Homework Statement Compute the inverse Laplace transform of Homework Equations http://img267.imageshack.us/img267/696/66451772.png The Attempt at a Solution I tried using partial fraction but no luck.
  29. L

    Use of Dirac delta to define an inverse

    I was wondering which are the properties of functions defined in such a way that ∫dx f(y-x) g(x-z) = δ(y-z) where δ is Dirac delta and therefore g is a kind of inverse function of f (I see this integral as the continuous limit of the product of a matrix by its inverse, in which case the...
  30. E

    Integration of exponential of inverse tangent

    Hi all, i need help with integration of exponential of inverse tangent, could not find it in table of integrals the whole equation is I=∫A/[w(a+z^2)^1/2]*exp(zb)*exp[(-i*arctan(z/(a)^1/2)] -am trying to integrate by parts but stuck at the arctan part Thank you.
  31. P

    Question about integration with inverse trigonometric functions

    I'm self-studying Calculus and would like to ask some doubts about the following question: Homework Statement If, in t seconds, s is the oriented distance of the particle from the origin and v is the velocity of the particle, then a differential equation for harmonic simple motion is...
  32. M

    Why Are All Singularities of the Laplace Transform Left of the Line Re(s)=c?

    f(t)=\int^{c+i\infty}_{c-i\infty}F(s)e^{st}ds Why we suppose that all singularities are left from line Re(s)=c?
  33. E

    Calculating the Inverse Discrete time Fourier transform

    Homework Statement Let the DTFT (Discrete time Fourier transform) of a signal beY(f)= {1 0≤lfl< \frac{fs}{8} {0 OtherwiseCalc y(k) Homework Equations y(k)=\frac{1}{f_{s}}\int Y(f) e^{jk2\pi fT}df lkl≥0 The Attempt at a Solution So what I understand from this is that my Y(f) is basically 1...
  34. R

    Understanding the Inverse Laplace Transform of Fractional Expressions

    Homework Statement I'm attempting to find the inverse laplace transform of (5/((2x+3)(4+x^2))) The Attempt at a Solution Here's the solution: http://www.wolframalpha.com/input/?i=inverse+laplace+transform+%285%2F%28%282x%2B3%29%284%2Bx%5E2%29%29%29 There's 3 terms in the solution and 2 are...
  35. J

    Solving an Inverse FT: ω0 = ∏/4, y(t) = p_4(t)sin(πt/4)?

    Hi, quick question regarding my solution of this Inv. FT: Y(\omega) = \frac{1}{j}[sinc(\frac{2\omega}{\pi} - \frac{1}{2}) - sinc(\frac{2\omega}{\pi} + \frac{1}{2})] Recognizing that that this looks a lot like this property of the FT: x(t)sin(\omega_{0}t) \leftrightarrow \frac{j}{2}[X(\omega +...
  36. D

    Fraction of Elements in a group mapped to own inverse by automorphism

    Q: Given a fraction A/B when does there exist a finite group G and an automorphism f s.t. exactly A/B elements of G are mapped to their own inverses (f(a) = a-1? If so how can we find the group? Does anything change if we allow infinite groups? I have a friend who was preparing for an intro...
  37. D

    Inverse Muon Decay differential cross section

    Why is it that the differential cross section for processes like Inverse Muon Decay (IMD) are always given in the CM frame? Every paper I have seen that discusses Inverse Muon Decay gives the differential cross section in CM frame. Is it very hard to calculate the differential cross section in...
  38. B

    How do I find the inverse of x^3/x^2+1?

    Hello, I have been working on this problem for a while now and can't seem to get it into a forum which would isolate x, which would then allow me to sub y and find the inverse. The problem is x^3/x^2+1 Can anyone help me with this? I am utterly stuck I have dealt with a similar...
  39. A

    Linear transformaton and inverse

    Homework Statement If T : V → W is an injective linear transformation, then T^-1: V →W is a linear transformation. The Attempt at a Solution Let w1, w2 in W. If w1=T(v1) and w2=T(v2), v1=/=v2 in V. Thus, T^-1: V →W is a function. Then, v1+v2=T^-1(w1) + T^-1(w2) and for a in F...
  40. Z

    Is the Function f(x) = -sin(-x) Invertible on the Interval -π to π?

    Homework Statement Determine if the following function is invertible. If it is, find the inverse function. f (x) = -sin(-x) -∏ < x < ∏ The Attempt at a Solution f(x) = -sin(-x) y = -sin(-x) -(sin y)^-1 = -x (sin y)^-1 = x when x = -∏, y = 0 when x = ∏, y = 0 f^-1(x)...
  41. T

    Inverse Power Method and Eigenvectors

    Homework Statement The Markov matrix A = [.9 .3; .1 .7] has eigenvalues 1 and .6, and the power method uk=Aku0 converges to [.75 .25]T. Find the eigenvectors of A-1. What does the inverse power method u-k=A-1u0 converge to (after you multiply by .6k)? Homework Equations The...
  42. A

    Finding intersection between exponential and inverse function

    Homework Statement Given the exponential function and its inverse, where a > 0 Exponential Function: f(x)=a^x Inverse function: f^{-1}(x)=log_ax a) For what values of a do the graphs of f(x)=a^x and f^(-1)(x) intersect?The Attempt at a Solution I have no idea how to start this question. Off...
  43. Z

    Inverse Function - algebra problem

    Homework Statement I'm trying to find the inverse function of the following. f(x) = [x^2 - 9]^0.5 x <= -3 The Attempt at a Solution In the book I'm using it gives the inverse function as; y = -(x^2 + 9)^0.5 [0, +∞) Is this correct, as I'm getting an inverse...
  44. K

    How Do You Apply Shifting in Inverse Laplace Transforms?

    Hello everyone, I'm currently enrolled in Control Theory at my University, and part of the coursework requires differential equations; which wouldn't be a problem, if not for the fact it's been 2 years since I've taken D.E. Anyway, over the course of the problem I ran into this little function...
  45. K

    How Do You Find the Inverse Laplace Transform of (1/6)/((s+2)^2)?

    Hello everyone, I'm currently enrolled in Control Theory at my University, and part of the coursework requires differential equations; which wouldn't be a problem, if not for the fact it's been 2 years since I've taken D.E. Anyway, over the course of the problem I ran into this little function...
  46. T

    Proving an equivalence relation using inverse functions

    Homework Statement Let f : A → B be a function and let Γ ⊂ B × B be an equivalence relation on B. Prove that the set (f × f)^-1 (Γ) ⊂ A × A (this can be described as {(a, a′) ∈ A × A|(f(a), f(a′)) ∈ Γ}) is an equivalence relation on A.Homework Equations The Attempt at a Solution Let...
  47. DryRun

    Find all solutions of inverse sine (-1/2)

    Homework Statement Find all solutions of inverse sine (-1/2). Angles lie between 0 and 2∏. The attempt at a solution I know it sounds very simple, but i must be having some of the basics wrong, as i can't figure out the second solution. I used the calculator (in radian mode) to find inverse...
  48. M

    Find the inverse laplace transform of this function

    Homework Statement F(s) = 3/(s(s^2 +2s + 5)) Homework Equations The Attempt at a Solution I have used partial fraction using coefficients. F(s) = (3/5)s - (3/5) ((s+2)/(s^2 +2s + 5)) and reduce s^2 +2s +5 by completing the square F(s) = (3/5)s - (3/5) ((s+2)/((s+1)^2 + 4))...
  49. E

    How is green's function a right inverse to the operator L?

    the definition of a green's function is: LG(x,s)=δ(x-s) the definition of a right inverse of a function f is: h(y)=x,f(x)=y→f°h=y how does it add up?
  50. P

    Is this inverse function continuity proof consistent?

    I am self-studying Calculus and tried to solve the following question: Homework Statement Suppose that the function f is continuous and increasing in the closed interval [a, b]. Then (i) f has an inverse f-1, which is defined in [f(a), f(b)]; (ii) f-1 is increasing in [f(a), f(b)]; (iii) f-1...
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