Miscelanea-1

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Across
  1. 4. Surface generated by the movement of a line
  2. 6. Numbers of the form n(n+1)/2
  3. 8. Famous collaborator of Hardy
  4. 11. British statistician that used the pseudonym Student
  5. 13. Set formed by an unique element
  6. 15. Axial symmetry
  7. 19. Triangle having sides of different lenghts
  8. 20. Real number that is not the root of a polynomial with integer coefficient
Down
  1. 1. Rudimentary method for approximation of solutions of f(x)=0
  2. 2. Diagram representing the frecuency distribution of data in intervals
  3. 3. Function that generalizes the factorial
  4. 5. Sets with no common elements
  5. 7. Introduced decimal logarithms
  6. 9. Family name of Lewis Carroll
  7. 10. Intersection point of the perpendicular bisectors in a triangle
  8. 12. Number of the type 2^p-1 (p prime)
  9. 14. Sum of two or more vectors
  10. 16. Locally convex complete metrizable space
  11. 17. Transformation that preserves distance
  12. 18. Developed the method of indivisibles by Cavalieri