Inverse Definition and 1000 Threads

  1. I

    MHB Use the inverse function theorem to estimate the change in the roots

    Let $p(\lambda )=\lambda^3+a_2\lambda^2+a_1\lambda+a_0=(\lambda-x_1)(\lambda-x_2)(\lambda-x_3)$ be a cubic polynomial in 1 variable $\lambda$. Use the inverse function theorem to estimate the change in the roots $0<x_1<x_2<x_3$ if $a=(a_2,a_1,a_0)=(-6,11,-6)$ and $a$ changes by $\Delta...
  2. O

    What is the inverse triangle symbol represent?

    Homework Statement B=magnetic flux density . A is the vector potential of magnetic field. How to get the formula B=∇A Homework Equations http://en.wikipedia.org/wiki/Magnetic_moment The Attempt at a Solution B=magnetic flux density . A is the vector potential of magnetic field...
  3. shounakbhatta

    Kepler's planetary motion and inverse square law

    Hello, The inverse square law of Newton's gravitational force, is it somehow related to each other? I mean to say P^2 is directly prop.a^3. Is it from the third law that the derivation of inverse sq.law of G=M.m/R2 is derived? Thanks.
  4. 1

    Calculating the Inverse of AB: A^(-1)=[4,0;-2,2], B^(-1)=[-2,0;-2,3]

    Homework Statement Find the inverse of AB if A^(-1)= [4,0;-2,2] and B^(-1)=[-2,0;-2,3]. (See below for picture/additional information.)Homework Equations Inverse of AB = inverse of A*inverse of B The Attempt at a Solution Using above equation: (AB)^(-1) = [4,0;-2,2]*[-2,0;-2,3] =...
  5. V

    Inverse Weyl quantization of the projection operator.

    I am trying to solve the following problem on an old Quantum Mechanics exam as an exercise. Homework Statement Homework Equations I know that the trace of an operator is the integral of its kernel. \begin{equation} Tr[K(x,y)] = \int K(x,x) dx \end{equation} The Attempt at a...
  6. P

    Compute Inverse Derivative for f(x) = x^3/(x^2+1) | Algebraic Help"

    Homework Statement compute the inverse derivative of f(x) = x^3/(x^2+1)Homework Equations n/aThe Attempt at a Solution My issue is a purely algebraic one... getting the inverse function! Attempting to solve for x yields no results! y = x^3/(x^2+1) y(x^2+1) = x^3 yx^2 + y = x^3 y = x^3 - yx^2 y...
  7. C

    Help needed, rearranging polynomial for inverse equation

    Hi, I need to rearrange an equation: y = ax^2 + bx + c to the form of: x = ? I'm not entirely sure how to go about this and the examples I've found require the equation to be in a different form. Any tips or a point in the right direction would be great! Thanks in advance
  8. M

    Need help with truth table for P->Q and it's inverse

    Hi! I'm struggling with the bellow truth tables: P = I live in Paris Q = I live in France A B C P → Q Q → P ¬ Q → ¬ P S S S S S S F S F S F F F S S S F F F S S S F F F S S F S F F S F S S S Table A and C I'm...
  9. S

    Lumped parameters model: inverse dynamic

    Hi all, I have a ground excited single degree of freedom model, like that: http://www.bsw-schwingungstechnik.de/fileadmin/user_upload/images/2/graphic-passiv-isolation.jpg I know the excitation function, i.e. s(t), but I need to know the force that imposes a specific s(t). I need it...
  10. F

    Why does the E-field of radiation vary with inverse distance?

    Feynman_Lectures_on_Physics_Volume_1_Chapter_28 In 28-2 Radiation Feynman starts talking about the third term of Eq. 28.3 and why that it varies with the inverse of the distance. On page 28-4 he says that the unit vector e'r is pointed to the apparent position of the charge. I understand...
  11. J

    How does distance affect light intensity according to the inverse square law?

    Homework Statement I have a general question about light and Lumens and the inverse square law? So Intensity = Initial Lumens/Lenth^2 So @ a Length of 1, there is no loss of light intensity. What unit is this 1. 1 meter? 1 foot? Homework Equations The Attempt at a...
  12. C

    Does EM Radiation Dissipate at a 1/r^5 Ratio for Circularly Polarized Waves?

    inverse square vs cube = ? If the electric field falls off at the inverse square ratio, and magnetic at inverse cube, does EM radiation dissipate at 1/r^5 ratio for circularly polarized waves?
  13. Coelum

    Inverse Jacobi Matrix in Spherical Coordinates

    Dear all, I am reading R.A. Sharipov's Quick Introduction to Tensor Analysis, and I am stuck on the following issue, on pages 38-39. The text is freely available here: http://arxiv.org/abs/math/0403252. If my understanding is correct, then the Jacobi matrices for the direct and inverse...
  14. Y

    Inverse Tangent Question: Impact of Positive and Negative Delta on Psi with Time

    \Psi=\tan^{-1}\left(\frac{\cos\omega t}{\cos(\omega t+\delta)}\right) I want to find out whether ##\Psi## increase or decrease with time t, if ##\delta## is positive and if ##\delta## is negative. \Psi=\tan^{-1}\left(\frac{\cos\omega t}{\cos(\cos\omega t \cos \delta+\sin\omega t...
  15. R

    Linear Algebra Matrix Inverse Proof

    Homework Statement Let A be a square matrix. a. Show that (I-A)^-1 = I + A + A^2 + A^3 if A^4 = 0. b. Show that (I-A)^-1 = I + A + A^2 + ... + A^n if A^(n+1) = 0. Homework Equations n/a The Attempt at a Solution I thought I'd want to use the fact that the multiplication of a...
  16. H

    Variational Method vs Inverse Rayleigh Method with Shifting

    I must fundamentally misunderstand what the variational method is. According to my textbook, it's used to find the minimum eigen energy of an operator (in particular, the time-independent schrodinger equation). This appears to be synonymous to finding the eigenvalues of the matrix representation...
  17. MarkFL

    MHB Rebekah's question at Yahoo Answers involving inverse trigonometric functions

    Here is the question: Here is a link to the question: Given 0<x<orequalto 1, determine the value of inversine (x) + inversetan (squareroot(1-x^2)/x)? - Yahoo! Answers I have posted a link there to this topic so the OP may find my response.
  18. MarkFL

    MHB Inverse Functions & Newton's Method: Debmnzl's Question | Yahoo! Answers

    Here is the question: Here is a link to the question: A math function question please help? - Yahoo! Answers I have posted a link there to this topic so that the OP may find my response.
  19. N

    Matrix and inverse matrix question?

    Homework Statement how do I solve this question https://www.dropbox.com/s/bn958xnm5483s6u/photo%20%281%29.JPG (This link if the image is not visible : https://www.dropbox.com/s/bn958xnm5483s6u/photo%20%281%29.JPG) just so the equation is not clear it says A2 = λA - 2I The inverse should be...
  20. I

    Inverse Laplace of 1s: Formula-Based Solution

    This is very tricky for me. How to find the inverse laplace of 1s. I haven't been taught the integral method of inverse. Only the formula based , splitting terms kind of thing. I used MATLAB and found it was dirac delta. But how do I get to it without using the integral for inverse?
  21. T

    Laplace and inverse laplace transformation of unit step functions u(t).

    Homework Statement So I have this laplace transformation chart and was a bit unsure about the laplace and inverse laplace of this. The unit step function, where u(t) = 0 where t < 0, u(t) = 1 where t > 0. The laplace transformation chart that I have has two columns, the column on the...
  22. M

    Having a problem with inverse proportion

    Reaaly need to solve these
  23. I

    Finding the Inverse Laplace Transformation

    Homework Statement find the inverse laplace transformation of \frac{5s+4}{s^2} e^{-2s} Homework EquationsThe Attempt at a Solution I have tried to partial fractions \frac{5s+4}{s^2} and I got \frac{5}{s}+\frac{4}{s^2} and I know that the answer must have u(t-2) because of second shifting (...
  24. D

    Is This the Correct Approach to Solving an Inverse Laplace Transform?

    Homework Statement Could anyone please check my work, The answer is wrong. Correct Answer: e^2t(-t+e^t-1) Homework Equations Inverse Laplace The Attempt at a Solution Here's my solution, please point out my mistakes. One mistake i found after taking the picture is: Its -2te^-2t ( third...
  25. B

    Inverse of Metric in Topology: Schwarz Inequality

    In Topology: is the multiplicative inverse of a metric, a metric? How do we define the Schwarz inequality then? if ##d(x,z) ≤ d(x,y) + d(y,z)## the inverse ##1/d(x,z)## would give the opposite?
  26. X

    Factoring in Inverse Laplace Transformations

    Homework Statement see attachment Homework Equations The Attempt at a Solution I don't get the part where it says "Solving this equation for X(s), we obtain ..." Specifically jumping from 3/s(s2+3s+5) to (3/5)(1/s)-(3/5)[(s+2)/(s2+2s+5)]. How did the problem break up this...
  27. E

    If ad = bc, then the (abcd) matrix has no inverse

    This is problem 4.14 in Advanced Calculus of Several Variables. Two questions: Is my proof correct? And: is there a cleaner way to prove this? Show that, if ad = bc , then the matrix \left [ \begin{array}{cc} a & b \\ c & d \\ \end{array} \right] has no inverse. My attempt: Suppose there is...
  28. T

    Trigonometric Inverse Substitution: How do we know which substitutions to use?

    If we see the form \sqrt { { a }^{ 2 }-{ x }^{ 2 } }, we always set x=asinθ How do we know that it will work in advance? Just trial & error?
  29. F

    Computational cost of calculating an inverse via Gauss-Jordan

    Homework Statement Find the computational cost for finding the inverse of an nxn matrix via Gauss-Jordan elimination. That is setting up A|I and converting it to I|A-1.Homework Equations The Attempt at a Solution So I can't see where I went wrong, but my answer does not agree with my fellow...
  30. M

    Linear algebra inverse of a matrix

    Homework Statement The matrix given is row 1: [0,1] row 2: [1,0] The matrix above if you switch row 1 with row 2 is just the identity matrix. So wouldn't that matrix already be the inverse of the identity matrix? Homework Equations The Attempt at a Solution
  31. B

    Prove Inverse of a bijective function is also bijective

    Homework Statement Prove that the inverse of a bijective function is also bijective. Homework Equations One to One f(x_{1}) = f(x_{2}) \Leftrightarrow x_{1}=x_{2} Onto \forall y \in Y \exists x \in X \mid f:X \Rightarrow Y y = f(x) The Attempt at a Solution It...
  32. T

    Solving a system with the inverse of a matrix.

    Homework Statement a)Use Gauss-Jordan elimination to find the inverse of A = [ 2 1 4 ] [ 1 1 2 ] [ -2 -3 -2 ] b) Use the result from part a) to find the solution of the following system. 5x+2y-3z = 5 x+y-z = -1 -3x-y+2z = 2 Homework Equations The Attempt...
  33. H

    A continuous function having an inverse <=> conditions on a derivative?

    Sorry for the poorly-worded title. I help tutor kids with pre-calculus, and they're working inverse functions now. They use the "horizontal line test" to see if a function will have an inverse or not by seeing visually if it's one-to-one. I was thinking about what that might imply. If a...
  34. I

    MATLAB Inverse laplace in matlab gives iota

    I'm applying laplace transform to a spring-mass system, the most basic one. I write this code which takes initial values x(0) and v(0) as input and I'm computing x(t) in matlab. But for some values it gives me complex roots for x(t) which doesn't seem possible. If not for laplace I can solve the...
  35. D

    Pseudo inverse very inaccurate

    Hi, I've a very trivial numerical problem where I'm currently stuck. In MATLAB the matrix Hf: >> Hf Hf = 1.0e+003 * 1.6443 1.6516 1.6583 4.8373 4.8349 4.8334 4.6385 4.6418 4.6445 -9.6014 -9.6084 -9.6154 And the following vectors which...
  36. U

    Inverse trigonometry prove this

    Homework Statement If cos^{-1}\frac{x}{a}+cos^{-1}\frac{y}{b} = \alpha then show that \frac{x^2}{a^2}-\frac{2xy}{ab}cos \alpha + \frac{y^2}{b^2} = sin^2 \alpha Homework Equations The Attempt at a Solution I assume inverse functions to be θ and β respectively. So in the second equation...
  37. A

    Inverse of a Matrix - Understanding Why We Note Relatively Prime Expressions

    In this video: At the time 2:10, I don't understand why we have to note that \lambda^3 - 8\lambda and \lambda^2 + 1 are relatively prime. Thanks in advance
  38. U

    Inverse trigonometric equation

    Homework Statement Solve cot^{-1} x - cot^{-1} (n^2 - x+1)=cot^-1(n-1) Homework Equations The Attempt at a Solution I can write the above equation as θ+α=β where the symbols represent the respective inverse functions. Now I take tan of both sides. Simplifying I get...
  39. B

    Matrix manipulation (inverse, lin. alg.)

    Homework Statement Let A\inM_{n}(\Re) a matrix verifying A^{3}-A^{2}-I_{n}=0 a) Show that A is inversible and calculate it b) Show that the solution X\subsetM_{n}(\Re) of the equation A^{k}(A-I_{n})X=I_{n} has a unique solution. The Attempt at a Solution I'm having...
  40. S

    What is the inverse of this logarithm equation?

    Homework Statement What is the inverse of this logarithm equation? y=-log5(-x) i tried it and i got y=-5(-x)hm.. you know how people say that if you want to find the inverse graph of something just switch the x and y coordinates from the table of values? Well i also tried that approach and...
  41. Y

    MHB Proving the Inverse of the Adjoint Matrix Property for nxn Matrices

    Hello I need some help proving the next thing, I can't seem to be able to work it out.. Let A be an nxn matrix. Prove that: (adj A)^{-1} = adj(A^{-1}) Thanks...
  42. A

    Inverse 2D rotation with negative parameters

    Homework Statement Say we have a 2D rigid body transform, with parameters p = [ p_1,p_2,p_3] for rotation, x translation and y translation respectively. I'm using the transform to .. transform an image. Is there a way to have: For a point x , y : x',y' = transform(x,y,p) <=> x,y =...
  43. R

    Inverse Laplace Transform of (1/(s+s^3))?

    Homework Statement What is the inverse laplace transform of (1/(s+s^3))? Homework Equations The Attempt at a Solution I looked it up on wolframalpha and got 1-cos(t), but I don't understand how they got that answer. I looked up a basic laplace transform chart and didn't see anything...
  44. B

    Understanding the Derivative Rule for Inverses

    Homework Statement Assume that the Derivative Rule for Inverses holds. Given that f(x) = x + f(x), and g(t) = f-1(t), which of the following is equivalent to g'(t)? a. g'(t) = 1 + t2 b. g'(t) = 1 + t4 c. g'(t) = 1 + g(x) d. g'(t) = 1 / (1 + t4) Homework Equations The Attempt at a...
  45. M

    How to find inverse Laplace transform?

    Homework Statement Find inverse Laplace transform \mathcal {L}^{-1}[\frac{1}{(s^2+a^2)^2}]Homework Equations The Attempt at a Solution I try with theorem \mathcal{L}[f(t)*g(t)]=F(s)G(s) So this is some multiple of \mathcal{L}[\sin at*\sin at] So \mathcal {L}^{-1}[\frac{1}{(s^2+a^2)^2}]=\propto...
  46. C

    A question regarding inverse functions

    Hi I'm reading a book called Calculus lifesaver, and in the book they state that the inverse of a function f(x)= x3 is the same as f-1(x)=3√x and is the same as f-1(y)=3√y So I did a test, with a simpler function and I can't see how this is true If I have a function f(x)= 2*x Then...
  47. K

    Find the Inverse of a Function: f-1(f(x)) = +/-√(x+0.25)-1.5

    Homework Statement Given f(x) = x2+3x+2, what is f-1(f(x))? Homework Equations The Attempt at a Solution Algebraically, getting f-1(x) is as follows: y=x2+3x+2 x=y2+3x+2 y=+/-√(x+0.25)-1.5 f-1(x)=+/-√(x+0.25)-1.5 f-1(f(x))=+/-√(x2+3x+2+0.25)-1.5...
  48. mnb96

    Question on Jacobian with function composition and inverse functions

    Hello, let's suppose I have two functions \phi:U\rightarrow V, and T:V\rightarrow V that are both diffeomorphisms having inverse. Furthermore T is linear. I consider the function f(u) = (\phi^{-1}\circ T \circ \phi)(u), where \circ is the composition of functions. Since T is linear, we...
  49. S

    Proving Inverse Function Continuity: A Topological Challenge

    Homework Statement Prove that if the inverse of a function between topological spaces maps base sets to base sets, then the function is continuous. Homework Equations I have no idea. The Attempt at a Solution I seriously have no idea. This is for my analysis course, and I'm not...
Back
Top