1. Integral of 1/(x^2+1) by using complex number

    Integral of 1/(x^2+1) by using complex number

    28
    4
    20
  2. Linear map fixed point theorem

    Linear map fixed point theorem

    43
    2
    7
  3. The existence proof of eigenvectors and eigenvalues

    The existence proof of eigenvectors and eigenvalues

    9
    2
    2
  4. Integral of 1/(1+x^2)^2 (substitution)

    Integral of 1/(1+x^2)^2 (substitution)

    12
    3
    1
  5. Very funny math question solve x for x^x^n=n

    Very funny math question solve x for x^x^n=n

    24
    3
  6. Prove Method of infinite Descent : square 2 is irrational

    Prove Method of infinite Descent : square 2 is irrational

    16
    4
    2
  7. Prove Method of infinite Descent : no nontrivial solutions x^2+y^2=3z^2

    Prove Method of infinite Descent : no nontrivial solutions x^2+y^2=3z^2

    22
    2
    1
  8. Prove Method of infinite Descent (Vieta's jumping) : (4a^2-1)^2/(4ab-1) is integer, then a=b

    Prove Method of infinite Descent (Vieta's jumping) : (4a^2-1)^2/(4ab-1) is integer, then a=b

    21
    4
  9. Prove Method of infinite Descent : square k is irrational if k is not square free

    Prove Method of infinite Descent : square k is irrational if k is not square free

    14
    4
    2
  10. sinx+sin2x+sin3x+...+sin nx, cosx+cos2x+cos3x+cos 4 x+...+cos nx

    sinx+sin2x+sin3x+...+sin nx, cosx+cos2x+cos3x+cos 4 x+...+cos nx

    16
    2
    1
  11. Prove Method of infinite Descent (Vieta's jumping) : (a^2+b^2)/(ab+1) is square, imo1988

    Prove Method of infinite Descent (Vieta's jumping) : (a^2+b^2)/(ab+1) is square, imo1988

    14
    4
  12. Normal subgroup and quotient subgroup

    Normal subgroup and quotient subgroup

    20
    5
  13. There exist distinct integers x,y,z for which, x^2+y^2+z^2=14^n

    There exist distinct integers x,y,z for which, x^2+y^2+z^2=14^n

    21
    4
    1
  14. a_{n+2}=5a_{n+1}-6a_{n} Mathematical induction

    a_{n+2}=5a_{n+1}-6a_{n} Mathematical induction

    22
    4
    6
  15. zero morphism and kernel and cokernel

    zero morphism and kernel and cokernel

    12
    1
  16. Schrodinger equation and Klein Gordan equation continuity equation

    Schrodinger equation and Klein Gordan equation continuity equation

    33
    2
    7
  17. Cauchy's theorem for the abelian group, Sylow theorem for abelian group

    Cauchy's theorem for the abelian group, Sylow theorem for abelian group

    22
    5
    6
  18. Homomorphism of ring and ideal, quotient ring

    Homomorphism of ring and ideal, quotient ring

    20
    3
    7