1. 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
  2. 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
  3. 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
  4. Normal subgroup and quotient subgroup

    Normal subgroup and quotient subgroup

    20
    5
  5. 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
  6. a_{n+2}=5a_{n+1}-6a_{n} Mathematical induction

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

    22
    4
    6
  7. zero morphism and kernel and cokernel

    zero morphism and kernel and cokernel

    12
    1
  8. integral of lnx ln(1-x) from 0 to 1

    integral of lnx ln(1-x) from 0 to 1

    36
    6
    11
  9. Schrodinger equation and Klein Gordan equation continuity equation

    Schrodinger equation and Klein Gordan equation continuity equation

    33
    2
    7
  10. 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
  11. Homomorphism of ring and ideal, quotient ring

    Homomorphism of ring and ideal, quotient ring

    20
    3
    7
  12. Linear algebra advanced basic: Zorn's lemma, exchange lemma, dimension

    Linear algebra advanced basic: Zorn's lemma, exchange lemma, dimension

    29
    6
    57
  13. Integral of 1/(x^3-1) from integral of 1/(x^3+1)

    Integral of 1/(x^3-1) from integral of 1/(x^3+1)

    24
    3
    17
  14. Cayley's theorem and its generalization

    Cayley's theorem and its generalization

    1
  15. Group homomorphism and first group isomorphism theorem

    Group homomorphism and first group isomorphism theorem

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

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

    28
    4
    20
  17. Inner product space and p norm

    Inner product space and p norm

    35
    3
    3
  18. Probability solution: A Total of n balls, number of 1 through n...

    Probability solution: A Total of n balls, number of 1 through n...

    40
    5
    17