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

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

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

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

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

    Prove Method of infinite Descent : square 2 is irrational

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  4. 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

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  5. 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

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  6. 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

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    2
  7. 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

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  8. 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

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  9. Normal subgroup and quotient subgroup

    Normal subgroup and quotient subgroup

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  10. 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

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  11. zero morphism and kernel and cokernel

    zero morphism and kernel and cokernel

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  12. Schrodinger equation and Klein Gordan equation continuity equation

    Schrodinger equation and Klein Gordan equation continuity equation

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

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

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  14. Homomorphism of ring and ideal, quotient ring

    Homomorphism of ring and ideal, quotient ring

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  15. Polynomial ring over rationals

    Polynomial ring over rationals

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  16. Polynomial over a commutative ring

    Polynomial over a commutative ring

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