1. Jerzy K. Baksalary & Oskar Maria Baksalary

Solution 25-1.1 (to Problem 25-1 “Moore Penrose inverse of a skew-symmetric matrix” proposed by Jürgen Groβ, Sven-Oliver Troschke & Götz Trenkler). IMAGE 26 (2001) 2.

2. Jerzy K. Baksalary & Oskar Maria Baksalary

Solution 25-4.1 (to Problem 25-4 “Two rank equalities associated with blocks of an orthogonal projector” proposed by Yongge Tian). IMAGE 26 (2001) 6-7.

3. Jerzy K. Baksalary & Oskar Maria Baksalary

Solution 25-5.1 (to Problem 25-5 “Three inequalities involving Moore—Penrose inverses” proposed by Yongge Tian). IMAGE 26 (2001) 9-10.

4. Jerzy K. Baksalary & Oskar Maria Baksalary

Solution 25-6.1 (to Problem 25-6 “Generalized inverse of a matrix product” proposed by Yongge Tian). IMAGE 26 (2001) 10-11.

5. Jerzy K. Baksalary & Oskar Maria Baksalary

Solution 26-4.1 (to Problem 26-4 “Commutativity of EP matrices” proposed by Yongge Tian). IMAGE 27 (2001) 30.

6. Jerzy K. Baksalary & Oskar Maria Baksalary

Solution 26-5.1 (to Problem 26-5 “Convex matrix inequalities” proposed by Bao-Xue Zhang). IMAGE 27 (2001) 33-34.

7. Jerzy K. Baksalary & Oskar Maria Baksalary

Problem 29-1 “A condition for an EP matrix to be Hermitian”. IMAGE 29 (2002) 36.

8. Jerzy K. Baksalary & Oskar Maria Baksalary

Solution 27-2.1 (to Problem 27-2 “Specific generalized inverses” proposed by Jürgen Groβ and Götz Trenkler). IMAGE 28 (2002) 29.

9. Jerzy K. Baksalary & Oskar Maria Baksalary

Solution 28-5.1 (to Problem 28-5 “A range equality for Moore—Penrose inverses” proposed by Yongge Tian). IMAGE 29 (2002) 28-29.

10. Jerzy K. Baksalary & Oskar Maria Baksalary

Solution 28-7.2 (to Problem 28-7 “Partial isometry and idempotent matrices” proposed by Götz Trenkler). IMAGE 29 (2002) 31.

11. Oskar Maria Baksalary

Solution 28-2.2 (to Problem 28-2 “Linear combinations of imaginary units” proposed by Richard William Farebrother). IMAGE 29 (2002) 26. Correction from the author: IMAGE 30 (2003) 21.

12. Jerzy K. Baksalary & Oskar Maria Baksalary

Solution 29-5.1 (to Problem 29-5 “Product of two Hermitian nonnegative definite matrices” proposed by Jürgen Groβ). IMAGE 30 (2003) 24-25.

13. Jerzy K. Baksalary & Oskar Maria Baksalary

Solution 30-5.1 (to Problem 30-5 “A range equality for the difference of orthogonal projectors” proposed by Yongge Tian). IMAGE 31 (2003) 36-37.

14. Jerzy K. Baksalary & Oskar Maria Baksalary

Solution 30-6.1 (to Problem 30-6 “A matrix related to an idempotent matrix” proposed by Götz Trenkler). IMAGE 31 (2003) 39.

15. Jerzy K. Baksalary & Oskar Maria Baksalary

Solution 30-7.1 (to Problem 30-7 “A condition for an idempotent matrix to be Hermitian” proposed by Götz Trenkler). IMAGE 31 (2003) 41.

16. Jerzy K. Baksalary, Oskar Maria Baksalary & Xiaoji Liu

Problem 30-1 “Star partial ordering, left-star partial ordering, and commutativity”. IMAGE 30 (2003) 36.

17. Jerzy K. Baksalary, Oskar Maria Baksalary & Xiaoji Liu

Solution 30-1.1 (to Problem 30-1 “Star partial ordering, left-star partial ordering, and commutativity” proposed by Jerzy K. Baksalary, Oskar Maria Baksalary & Xiaoji Liu). IMAGE 31 (2003) 30-31.

18. Oskar Maria Baksalary & Katarzyna Chyli??ska

Solution 29-10.2 (to Problem 29-10 ??Equivalence of three reverse-order laws? proposed by Yongge Tian). IMAGE 30 (2003) 31-32.

19. William F. Trench, Jerzy K. Baksalary & Oskar Maria Baksalary

Solution 29-1.2 (to Problem 29-1 “A condition for an EP matrix to be Hermitian” proposed by Jerzy K. Baksalary & Oskar Maria Baksalary). IMAGE 30 (2003) 22.

20. Jerzy K. Baksalary & Oskar Maria Baksalary

Solution 31-7.1 (to Problem 31-1 On the product of orthogonal projectors proposed by Götz Trenkler). IMAGE 32 (2004) 30-31.

21. Jerzy K. Baksalary, Oskar Maria Baksalary & Xiaoji Liu

Solution 31-2.1 (to Problem 31-2 “Matrices commuting with all nilpotent matrices” proposed by Henry Ricardo). IMAGE 32 (2004) 21-22.

22. Oskar Maria Baksalary

Solution 31-8.1 (to Problem 31-8 “Eigenvalues and eigenvectors of a particular tridiagonal matrix” proposed by Fuzhen Zhang). IMAGE 32 (2004) 37.

23. Oskar Maria Baksalary

Solution 33-6.1 (to Problem 33-6 “Projectors and similarity” proposed by Götz Trenkler). IMAGE 34 (2005) 35.

24. Oskar Maria Baksalary

Solution 34-9.2 (to Problem 34-9 “A sum property for the Moore—Penrose inverse of EP matrices” proposed by Götz Trenkler). IMAGE 35 (2005) 41.

25. Oskar Maria Baksalary & Xiaoji Liu

Solution 34-8.1 (to Problem 34-8 “A property for the sum of a matrix A and its Moore—Penrose inverse A” proposed by Götz Trenkler). IMAGE 35 (2005) 39-40.

26. Oskar Maria Baksalary & Xiaoji Liu

Solution 34-10.1 (to Problem 34-10 “On the product of orthogonal projectors” proposed by Götz Trenkler). IMAGE 35 (2005) 42.

27. Oskar Maria Baksalary & Xiaoji Liu

Solution 35-7.1 (to Problem 35-7 “A characterization of oblique projectors” proposed by Götz Trenkler). IMAGE 36 (2006) 31.

28. Oskar Maria Baksalary & Xiaoji Liu

Solution 35-8.1 (to Problem 35-8 “A characterization of a particular class of square complex matrices” proposed by Götz Trenkler). IMAGE 36 (2006) 32-33.

29. Oskar Maria Baksalary & G??tz Trenkler

Problem 37-1 “Another property for the sum of a matrix A and its Moore—Penrose inverse A”. IMAGE 37 (2006) 32.

30. Oskar Maria Baksalary & G??tz Trenkler

Problem 37-2 ??Rank of a generalized projector?. IMAGE 37 (2006) 32.

31. Oskar Maria Baksalary & G??tz Trenkler

Problem 37-3 ??Rank of a nonnegative definite matrix?. IMAGE 37 (2006) 32.

32. Oskar Maria Baksalary & G??tz Trenkler

Solution 37-1.1 (to Problem 37-1 ??Another property for the sum of a matrix A and its Moore??Penrose inverse A?? proposed by Oskar Maria Baksalary & G??tz Trenkler). IMAGE 39 (2007) 23-24.

33. Oskar Maria Baksalary & G??tz Trenkler

Solution 37-2.1 (to Problem 37-2 ??Rank of a generalized projector? proposed by Oskar Maria Baksalary & G??tz Trenkler). IMAGE 39 (2007) 25-26.

34. Oskar Maria Baksalary & G??tz Trenkler

Solution 37-3.1 (to Problem 37-3 ??Rank of a nonnegative definite matrix? proposed by Oskar Maria Baksalary & G??tz Trenkler). IMAGE 39 (2007) 27.

35. Oskar Maria Baksalary & G??tz Trenkler

Solution 37-6.1 (to Problem 37-6 ??Characterization of EP-ness? proposed by G??tz Trenkler). IMAGE 39 (2007) 30.

36. Oskar Maria Baksalary & G??tz Trenkler

Problem 11379. The American Mathematical Monthly 115 (2008) 664.

37. Oskar Maria Baksalary & G??tz Trenkler

Problem 11387. The American Mathematical Monthly 115 (2008) 758.

38. Oskar Maria Baksalary & G??tz Trenkler

Problem 41-1 ??A lower bound for the rank of A + A*?. IMAGE 41 (2008) 42.

39. Oskar Maria Baksalary & G??tz Trenkler

Problem 41-2 ??An inequality involving a semi-inner product?. IMAGE 41 (2008) 42.

40. Oskar Maria Baksalary & G??tz Trenkler

Problem 41-3 ??A Property of the Range of Generalized and Hypergeneralized Projectors?. IMAGE 41 (2008) 43.

41. Oskar Maria Baksalary & G??tz Trenkler

Problem 41-12 ??An inequality involving a product of two orthogonal projectors?. IMAGE 41 (2008) 44.

42. Oskar Maria Baksalary, Roger Horn & G??tz Trenkler

Problem 41-13 ??Range Additivity of A and A*?. IMAGE 41 (2008) 43.

43. Oskar Maria Baksalary & G??tz Trenkler

Problem 882 ??An inequality with positive definite matrices?. The College Mathematics Journal 39 (2008) 307-308.

44. Oskar Maria Baksalary & G??tz Trenkler

Solution 39-5.1 (to Problem 39-5 “Two commutativity equalities for the regularized Tikhonov inverse” proposed by Yongge Tian). IMAGE 41 (2008) 37-38.

45. Oskar Maria Baksalary & G??tz Trenkler


Solution 39-6.1 (to Problem 39-6 “Two equalities for the Moore—Penrose inverse of a row block matrix” proposed by Yongge Tian). IMAGE 41 (2008) 40.

46. Oskar Maria Baksalary & G??tz Trenkler

Problem 42-1 “Square root of a product of two orthogonal projectors”. IMAGE 41 (2009) 40.

47. Oskar Maria Baksalary & G??tz Trenkler

Solution 41-1 (to Problem 41-1 “A lower bound for the rank of A + A*” proposed by Oskar Maria Baksalary & Götz Trenkler). IMAGE 42 (2009) 27-28.

48. Oskar Maria Baksalary & G??tz Trenkler

Solution 42-2 (to Problem 41-2 “An inequality involving a semi-inner product” proposed by Oskar Maria Baksalary & Götz Trenkler). IMAGE 42 (2009) 28.

49. Oskar Maria Baksalary, Roger Horn & G??tz Trenkler

Solution 41-13 (to Problem 41-13 “Range additivity of A and A*” proposed by Oskar Maria Baksalary, Roger Horn & Götz Trenkler). IMAGE 42 (2009) 37.

50. Oskar Maria Baksalary & G??tz Trenkler

Solution 42-2.1 (to Problem 42-2 “Properties of a certain matrix product” proposed by Richard William Farebrother). IMAGE 43 (2009) 37-38.

51. Oskar Maria Baksalary & G??tz Trenkler

Problem 43-1 “Characterization of EP matrices”. IMAGE 43 (2009) 44.

52. Oskar Maria Baksalary & G??tz Trenkler

Problem 44-1 “Constrained characterization of hermitianness”. IMAGE 44 (2010) 44.

53. Oskar Maria Baksalary & G??tz Trenkler

Problem 45-1 “Column space counterparts of the known conditions for orthogonal projectors”. IMAGE 45 (2010) 48.

54. Oskar Maria Baksalary & G??tz Trenkler

Solution 44-1.1 (to Problem 44-1 “Constrained characterization of hermitianness” proposed by Oskar Maria Baksalary & Götz Trenkler). IMAGE 45 (2010) 40.

55. Oskar Maria Baksalary & G??tz Trenkler

Problem 95.D. The Mathematical Gazette 95 (2011) 133.

56. Oskar Maria Baksalary & G??tz Trenkler

Problem 46-1 “Space decomposition in terms of column and null spaces”. IMAGE 46 (2011) 48.

57. Oskar Maria Baksalary & G??tz Trenkler

Solution 45-1.1 (to Problem 45-1 “Column space counterparts of the known conditions for orthogonal projectors” proposed by Oskar Maria Baksalary & Götz Trenkler). IMAGE 46 (2011) 39-40.

58. Oskar Maria Baksalary & G??tz Trenkler

Problem 47-2 “Another characterization of normality”. IMAGE 47 (2011) 40.

59. Oskar Maria Baksalary & G??tz Trenkler

Solution (to Problem 11466 proposed by Yongge Tian). The American Mathematical Monthly 119 (2012) 162-163.

60. Oskar Maria Baksalary & G??tz Trenkler

Problem 48-1 “Reverse Order Law for the Core Inverse”. IMAGE 48 (2012) 40.

61. Oskar Maria Baksalary & G??tz Trenkler

Problem 1904. Mathematics Magazine 85 (2012) 296.

62. Oskar Maria Baksalary & G??tz Trenkler

Problem 49-1 “Generalized eigenvalues of a pair of orthogonal projectors”. IMAGE 49 (2012) 52.

63. Oskar Maria Baksalary & G??tz Trenkler

Solution 48-2.1 (to Problem 48-2 “Minimality for the nonzero singular values of an idempotent matrix“ proposed by Johanns De Andrade Bezerra). IMAGE 49 (2012) 47.

64. Oskar Maria Baksalary & G??tz Trenkler

Aufgabe 1312. Elemente der Mathematik 68 (2013) 39.

65. Oskar Maria Baksalary & G??tz Trenkler

Problem 50-2 “Range-hermitianness of certain functions of projectors”. IMAGE 50 (2013) 44.

66. Oskar Maria Baksalary & G??tz Trenkler

Solution 50-2.2 (to Problem 50-2 ''Range-hermitianness of certain functions of projectors'' proposed by Oskar Maria Baksalary & Götz Trenkler). IMAGE 51 (2013) 43.

67. Oskar Maria Baksalary & G??tz Trenkler

Problem 52-2 “Numerical range of a skew-symmetric matrix”. IMAGE 52 (2014) 48.