Presents two papers commenting on previous published articles. Discusses formulas related to the determinants of sums and tests the formulas using some examples. Provides three special cases of the determinants of sums. (YP)

Presented is a derivation for the matrix representation of an arbitrary boost, a Lorentz transformation without rotation, suitable for undergraduate students with modest backgrounds in mathematics and relativity. The derivation uses standard vector and matrix techniques along with the well-known form for a special Lorentz transformation. (BT)

Provides an overview of a course, "Applied Linear Algebra," for teaching the concepts and the physical and geometric interpretations of some linear algebra topics. Describes the philosophy of the course, the computer project assignments, and student feedback. Major topics of the course are listed. (YP)

Describes research that was conducted to determine the search state patterns through which users retrieve information in hypertext systems. Use of the Markov model to describe users' search behavior is discussed, and search patterns of different user groups were studied by comparing transition probability matrices. (Contains 25 references.) (LRW)

Provides a program listing in True BASIC which constructs several kinds of matrices: (1) matrices with integral entries that have inverses that have integral entries; (2) matrices with integral entries that have inverses that are rational numbers with reasonable denominators; and (3) matrices with integral entries and prescribed integer…