Recent content by Andy_ToK

  1. A

    Solve Kinematics Problem: 3x Max Height, Find Angle

    your solution was right, all u have to do then is to plug it into your calculator and calculate arctan4/3
  2. A

    Momentum Eigenstates in 1D Infinite Square Well

    Thanks, Avodyne, but I'm not sure what u mean by "the Hilbert space consists of functions on the interval where the potential is zero". Could you elaborate a little bit?
  3. A

    Momentum Eigenstates in 1D Infinite Square Well

    Hi, I have a question about the momentum eigenstates in a 1D infinite square well example. First of all, are there any eigenstates at all in this example? By explicitly applying the wavefunction(stationary states) which can be easily obtained from the boundary conditions, it can shown that the...
  4. A

    Calculating Limits of Functions in R^2 or Higher Dimensions

    Thank you. HallsofIvy
  5. A

    Calculating Limits of Functions in R^2 or Higher Dimensions

    Thanks. well, if let h=r \cos \theta, k = r \sin \theta, lim_{(h,k)->(0,0)} \sqrt{\frac{hk}{h^2+k^2}}} can be simplified to lim_{r->0}\sqrt{\cos \theta\sin \theta} which is dependent on theta however, how should I proceed then?
  6. A

    Calculating Limits of Functions in R^2 or Higher Dimensions

    Hi, I'm sort of new to the calculation of limits of functions defined in R^2( or R^n, n>=2) exp. the limit of sqrt{hk/(h^2+k^2)} as (h,k) --> (0,0) I think it should be 1/sqrt(2) if we let h=k. but I'm not sure if this is the right approach. what about other limits in the form "0/0" as...
  7. A

    Continuous linear transformation

    Thanks quasar987 and ZioX I forgot to use T(x)-T(y)=T(x-y) for the linear transformation... let d=e/C then, |x-y|<d --> |T(x)-T(y)|=|T(x-y)<cd=e
  8. A

    Continuous linear transformation

    oops, it should be <=, thanks. AM=arithmetic mean RMS=root mean square AM<=RMS (the equality holds when |x1|=|x2|...=|xm|)
  9. A

    Continuous linear transformation

    1.Thanks for pointing that out, it should be the absolute value.:smile: 2.sorry i made a mistake there, it should be sum_i|xi|<sqrt(m)*sqrt(sum_i(xi^2)) by AM<RMS
  10. A

    Continuous linear transformation

    x is an element of R^m |T(x)|=|sum_i(xi*T(ei))|<=sum_i{xi(|T(ei)|)} let A=max{|T(e1)|,|T(e2)|...|T(em)|) then |T(x)|<=A*sum_i(xi)<A/sqrt(m)*sqrt(sum_i(xi^2))=A/sqrt(m)*|x| (AM<RMS) sorry, i don't know how to use latex here:frown:
  11. A

    Continuous linear transformation

    T is a linear transformation from R^m->R^n, prove that T is continuous. I have proved that there's always a positive real number C that |T(x)|<=C|x|. How shall I proceed then? Thanks~
  12. A

    How Is a Closed Set of Rational Numbers Defined?

    Thank you all.
  13. A

    How Is a Closed Set of Rational Numbers Defined?

    [0,1] is but A isn't, i think. because A doesn't contain those irrational numbers between 0 and 1.
  14. A

    How Is a Closed Set of Rational Numbers Defined?

    Hi, here is the question, if A is a closed set that contains every rational number r: [0,1], show that [0,1] is a subset of A. But, how could A be closed? If A is closed, R^n-A is open, so any point in R^n-A would have a open sphere around it and this open sphere wouldn't intersect A...
  15. A

    Integrate x^3/(x^5-1): Solutions

    hi, thanks. I have the answer but wonder how to solve it without using calculator. Sorry if I wasn't clear.
Back
Top