Terms Definition and 1000 Threads

  1. A

    MHB How can I express f(z) in terms of z using exponentials?

    Hello! I am stuck at the final step. How do I get x+iy from the equation? Help! I am so sorry for posting this question in a picture instead of writing it out, because I don't know how to write equations on here.
  2. M

    How can I express f(z) in terms of z?

    Hello! I am stuck at the final step. How do I get x+iy from the equation? Help! I am so sorry for posting this question in a picture instead of writing it out, because I don't know how to write equations on here.
  3. I

    MHB Finding Surface Area from Equation in Terms of x=g(y)

    if I am finding the surface area, and I am given the equation in term of x=g(y) about the x-axis, do i have to solve for y or can i just integrate in terms of y? would i just use dx/dy instead?
  4. B

    Finding delta in terms of epsilon-delta definition

    Homework Statement If f(x) = 3x+1 en assume δ > 0. Assume ε>0. Give a δ > 0 with the following property : |x-1|< δ => |f(x) - f(1)| < ε Homework Equations The Attempt at a Solution |f(x) - f(1)| < ε <=> |3x+1-(3*1+1)| < ε <=> |3x-3| < ε <=>...
  5. L

    Functioning of AC current in simple terms?

    Hi, Thank you for reading this. I understand the functioning of DC current. You create a potential difference and the electrons flow from the power source through the electrical appliance (thereby, powering it) and flows back, completing the circuit. But, in AC, the electrons...
  6. J

    Another vector fields in terms of circulation and flux

    Other laws in terms of circulation and flux Why others vector fields no are studied like the magnetic and electric fields? In other words, why others vector fields, like the gravitational and the hydrodynamic, haven't "supreme laws" based in the circulation/flux or curl/divergence?
  7. D

    Mathematica Collecting terms in mathematica

    I have an integrand with a handful of terms, and some of them have poles in the denominator of the form (x+c) (but not all). There are three poles in total, and I want to collect all the terms according to each pole individually (eg all the terms with (x-1) in the denominator, (x-5), etc.)...
  8. Govind_Balaji

    Prove a complex expression = 1, if log of the complex terms are equal

    Homework Statement If \frac{\log x}{b-c}=\frac{\log y}{c-a}=\frac{\log z}{a-b}, prove that x^{b+c-a}.y^{c+a-b}.z^{a+b-c}=1Homework Equations The Attempt at a Solution I solved a question similar to it in a way. So I tried this in the same way. The only difference between the two questions is...
  9. J

    Can the trace be expressed in terms of the determinant?

    Browsing in the wiki, I found those formulas: http://en.wikipedia.org/wiki/Determinant#Relation_to_eigenvalues_and_trace So, my doubt is: if is possible to express the determinant in terms of the trace, thus is possible to express the trace in terms of the determinant too?
  10. J

    How write a matrix in terms of determinant and trace?

    Given the following: $$\\ \begin{bmatrix} A & 0\\ 0 & B\\ \end{bmatrix}$$ the eigenvalues is exactaly A and B. So analogously, is possible to write a matrix with only two elements, T and D, such that the trace is T and the determinant is D? I tried something: $$\\ \text{tr} \left(...
  11. S

    Write sin in terms of Hermite polynomials

    Homework Statement Write ##sin(ax)## for ##a \in \mathbb{R}##. (Use generating function for appropriate ##z##) Homework Equations ##e^{2xz-z^2}=\sum _{n=0}^{\infty }\frac{H_n(x)}{n!}z^n## The Attempt at a Solution No idea what to do. My idea was that since...
  12. J

    Neglecting High-Order Terms in R: Tips & Tricks

    Hi, Is there a better way to write this? 'terms of order O(R^{-Y}) where Y>1 are neglected' I feel like this is a bit clumsy. Thanks for the help!
  13. E

    "Special" and "General" relativity- Who invented those terms?

    Hi all, I can't seem to find any historic account of when those two theories got their (quite strange) names. Can someone point me to a source? One of the reasons I am interested in this is the persistent idea in popularizing texts, especially from the 1970's, that Special Relativity could...
  14. W

    What are the independent terms in the Magnetic Tensor

    I am trying to understand the magnetic gradient tensor which has nine components. There are three magnetic field components, but there are also three baselines. These nine gradients are organised into a 3x3 matrix. I have read that only 5 of these terms are independent. What exactly does this...
  15. C

    Rotation and translation of basis to remove cross terms

    So in our notes we are given a general quadratic equation in three dimensions of the form: Ax^2 + By^2 + Cz^2 + Dxy + Eyz + Fxz + Gx + Hy + Iz + J = 0 And then they say, by some rotation we can change this to the standard form: Ax^2 + By^2 + Cz^2 + J = 0 The lecturer said don't worry...
  16. D

    Differential equation substituition of new terms

    Homework Statement for this question, i sub u=xy and try to eliminate y in my working.. but how should i proceed since the term ux cannot be separated Homework Equations The Attempt at a Solution
  17. J

    Can the sinh and cosh functions be expressed in terms of each other?

    Is possible express the sine in terms of cosine and vice-versa: ##\sin(x) = \cos(x-\frac{\pi}{2})## ##\cos(x) = \sin(x+\frac{\pi}{2})## So, of some way, is possible express the sinh in terms of cosh too and vice-versa?
  18. F

    Integral with exponential terms?

    I am doing some analysis and I have come up with the following integral: \int \frac{e^{-ax}}{1+be^{-cx}}dx where a>0, b>0 and c>0. I have found out this integral has a solution in terms of the Gaussian hypergeometric function http://en.wikipedia.org/wiki/Hypergeometric_function but it...
  19. L

    Find the sum of the first n terms

    Homework Statement Find the sum of the first n terms of the sequence U1, U2, U3... Ur Homework Equations The Attempt at a Solution $$ \sum_{r = 1}^n (1 + (-1)^r) = n + (-1)^n $$ But I don't this is right... any help?
  20. B

    Derivation of r (radius) in terms of f (frequency)? Help please.

    Okay, so the job I need to do is derive an equation for the radius of an object in terms of its frequency. These are the equations that we are allowed to use: v(Linear velocity) = rω v=2πr/T ω (angular velocity)=2πf f (frequency)= 1/T (time period) T= 2πr/v a (centripetal...
  21. L

    What is the formula for finding the sum to n terms in a geometric series?

    Homework Statement Wn = 2 + 3(1/2)^n Homework Equations The Attempt at a Solution I am confused, all I tried so far is writing out the first 5 terms, but all that was helping me to do is basically find the Sum to infinity... so what should I do to find the Sum to n terms? I know...
  22. Y

    Finding the tension in terms of mg

    Homework Statement Attached the question. Homework Equations (total) tension = mg The Attempt at a Solution I'm not sure how the tension gets divided here. I know the tension on the right hand side of the turnbuckle is the same tension on the left hand side since they are...
  23. S

    Summation of 'n' terms of the given expression

    Homework Statement find the general formula to calculate the sum Homework Equations 1+11+111+1111+11111+....upto n terms The Attempt at a Solution 100 + (101+100) + (102+101 + 100) + (103 + 102+101 + 100) + ... ==> (100+100+100+...upto n terms) + (101+101+101+...upto n-1 terms)...
  24. M

    MHB P divides all the coefficients of the terms with degree <8

    Hey! :o $f(x)=\sum_{i=0}^{7}{a_ix^i}, g(x)=\sum_{i=0}^{5}{b_ix^i}$, $a_i, b_i$ are integer coefficients. The prime $p$ divides $a_0, a_1, a_2, a_3, a_4$ but it does not divide $a_5, a_6, a_7$. $p$ divides also $b_0, b_1, b_2$, but it does not divide $b_3, b_4, b_5$. $h(x)=f(x)g(x)$ Show that at...
  25. J

    What is the difference between these types of differential equations?

    Which the difference between diff equations of kind: \frac{dy}{dx} = \exp(x) \frac{dy}{dx} = 1/x and diff equations of kind: \frac{dy}{dx} = y \frac{dy}{dx} = \frac{1}{\exp(y)} ?
  26. W

    What are independent terms in Magnetic Tensor

    I am trying to understand the magnetic gradient tensor which has nine components. There are three magnetic field components, but there are also three baselines. These nine gradients are organised into a 3x3 matrix. I have read that only 5 of these terms are independent. What exactly does this...
  27. nomadreid

    Velocity in Proper Time: Relativistic Acceleration Equation

    Two questions, based on the same situation: in http://physics.stackexchange.com/questions/34204/relativistic-acceleration-equation (question A) it is mentioned that, for an object with a constant acceleration g_{M}, and with \tau_{0} =1/g_{M} , after proper time \tau, the coordinates are...
  28. S

    Finding second derivative of sin y+cos y=x in terms of x

    Homework Statement Find the second derivative of sin y+cos y=x, giving your answer in terms of x. Homework Equations Implicit derivatives The Attempt at a Solution ##\sin y+\cos y=x## ##\cos y \frac{dy}{dx} -\sin y \frac{dy}{dx}=1## ##\frac{dy}{dx}=\frac{1}{\cos y-\sin y}##...
  29. Y

    MHB Solve Recurrence Relation w/ 3 Terms & Initial Conditions

    How to solve this question. Please explain step by step.
  30. S

    Density terms in the stress-energy momentum tensor

    The stress energy momentum tensor of the Einstein field equations contains multiple density terms such as the energy density and the momentum density. I know how to calculate relativistic energy and momentum, but none of the websites or videos that I have watched make mention of any division of...
  31. M

    Doppler Effect inconsistent in terms of relative velocities

    Hi all! Let me use an example to make this clear. There is a car traveling directly toward a man at 10m/s. The car is pressing down its horn, producing a frequency of 100hz. The speed of sound is 330 m/s. What frequency does the man hear? Ok, so we can use the equation: f_observer=(...
  32. R

    Hamiltons equations of motion in terms of poisson bracket

    In Hamiltonian formulation there is an expression df / dt = { f , H } + ∂f / ∂t where f is function of q, p and t. While expressing Hamiltons equations of motion in terms of Poisson Bracket, i.e if the function f = q of p then its partial time derivative ∂f / ∂t becomes zero.. Please explain why?
  33. Ryan_m_b

    Terms physicists and biologists use differently

    I'm giving a presentation to a group next week made up of mathematicians, physicists and mechanical engineers. My talk is going to be related to my work so it's going to be very biology based. I want to start the talk pointing out that life science and the physical sciences are very different in...
  34. H

    EFE Metric: Find a Link to the Full Expansion

    Does anyone have a link to a version of the EFE fully expanded in terms of the metric?
  35. A

    Answer: Limit of Big-O Terms: O(1/x) & O(x)

    I'm a bit confused with limits of big-O terms. What should be the answer for following:- 1) limit of O(1/x) as x->0. O(1) maybe but I'm not sure. 2) limit of O(x) as x-> 0. O(1) or 0?
  36. T

    3x^2 + 2x - k = 0, find 3α^2 - 2β in terms of k

    Homework Statement Let k be a constant. If α and β are the roots of the equation 3x^2 + 2x - k = 0, find the value of 3α^2 - 2β in terms of k. Homework Equations The Attempt at a Solution Obviously, the usual αβ = -k/3 α + β = -2/3 has been written but I couldn't put them...
  37. M

    Expand ψ(o) in terms of eignestates

    if ψ(o)=(1 0)^{T} at time t=0. According to some Hamiltonian, it was found that the corresponding eigenstates are |ø_{1}> = 1/√2(1 i)^{T} and |ø_{2}> = 1/√2(1 -i)^{T} so then we wanted to expand ψ(0) in terms of |ø_{1}> and |ø_{2}>: the author got: 1/√2|ø_{1}> + 1/√2 |ø_{2}> My question is...
  38. C

    Stress-energy tensor explicitly in terms of the metric tensor

    I am trying to write the Einstein field equations $$R_{\mu\nu}-\frac{1}{2}g_{\mu\nu} R=\frac{8\pi G}{c^4}T_{\mu\nu}$$ in such a way that the Ricci curvature tensor $$R_{\mu\nu}$$ and scalar curvature $$R$$ are replaced with an explicit expression involving the metric tensor $$g_{\mu\nu}$$...
  39. F

    Help with simplifing an equation in terms of 2 variables

    Homework Statement Hey. I need help simplifying and factoring a differential equation in terms of v and p (velocity(xdot) and position(x) respectively). I need the final answer to be in this form: a = ( )v + ( )p. This is so i can put the governing equation in a state-space and eventually use...
  40. J

    Taylor series in terms of discrete derivative

    All analitic function can be express how: f(x) = \frac{1}{0!} \frac{d^0f}{dx^0}(x_0) (x - x_0)^0 + \frac{1}{1!} \frac{d^1 f}{dx^1}(x_0) (x - x_0)^1 + \frac{1}{2!} \frac{d^2f}{dx^2}(x_0) (x - x_0)^2 + \frac{1}{3!} \frac{d^3f}{dx^3}(x_0) (x - x_0)^3 + ... that is the taylor series of the function...
  41. T

    Find the eigenstates of a basis in terms of those of another basis?

    Homework Statement This isn't exactly a homework question, but I figured this would be the best subforum for this sort of thing. For the sake of a concrete example, let's just say my question is: Express the position operator's eigenstates in terms of the number operator's eigenstates...
  42. C

    Expressing general rotation in terms of tensors

    Homework Statement A general rotation through angle ##a## about the axis ##\underline{n}##, where ##\underline{n}^2 = 1## is given by $$R(a,\underline{n}) = \exp(-ia\underline{n} \cdot \underline{T}),$$ where ##(T_k)_{ij} = -i\epsilon_{ijk}##. By expanding the exponential as a power series in...
  43. T

    Integral by interpreting it in terms of area

    Homework Statement ∫(a= -3 , b= 0) (1 + √9 - x^2) dx Homework Equations ∫(a,b) f(x) dx = lim as n → \infty \sum f(xi) delta x The Attempt at a Solution I tried plugging in my a and b value into the function just as I would with any other function to find the area and i get a number...
  44. T

    Non-canonical terms of scalar fields

    Hello! Well, I guess it's all in the title, really. I was reading about k-essence, and it was described as a scalar field having a non-canonical kinetic term. I did a bit of browsing and couldn't find a clear explanation of what, exactly, a non-canonical kinetic term is. Any help would be...
  45. C

    Representation of e in terms of primes

    We can represent π, in terms of primes by using Euler's product form of Riemann Zeta. For example ζ(2)=(π^2)/6= ∏ p^2/(p^2-1). Likewise, is there a representation of e that is obtained by using only prime numbers?
  46. kaliprasad

    MHB 3 consecutive terms of AP that are perfect square

    find parametetric representation of 3 perfect squares which are successive terms in AP ($x^2$,$y^2$,$z^2$) such that $x^2,y^2,z^2$ are successive terms of AP. find x,y,z
  47. B

    Pure, proper mixed, and improper mixed states in laymen's terms

    This is how one poster tried to explain it to me but for people who have only taken a basic physics course in college it leaves a lot wanting. "If a system is in a pure state, and you know what the pure state is, then your knowledge of the system is complete, and all uncertainty is quantum...
  48. 9

    Convergent limits for sequences: picture terms

    A limit of a sequence is definitely convergent if: If for any value of K there is an N sufficiently large that an > K for n > N, OR for any value of K there is an N sufficiently large that an<±K for n > N My only question is what exactly are K, N, an and n? What values are they? How would...
  49. N

    Finding inverse metric tensor when there are off-diagonal terms

    How do you find the inverse of metric tensor when there are off-diagonals? More specifivally, given the (Kerr) metric, $$ d \tau^2 = g_{tt} dt^2 + 2g_{t \phi} dt d\phi +g_{rr} dr^2 + g_{\theta \theta} d \theta^2 + g_{\phi \phi} d \phi^2 + $$ we have the metric tensor; $$ g_{\mu \nu} =...
  50. S

    What is the median value of an odd-numbered set of letters?

    I wonder what parts of statistics have specific terms existing for them - I see a relevant notion which would be relevant, but not sure if there is a term for it. If variable values can be ordered then it possesses a median. If the values can also be added then they also possesses an average. A...
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