Precalculus, a problems-oriented approach / David Cohen. Cohen, David, 1942 September 28- Precalculus. Problem solving. QA39.2 .C64 1984 512.1 19 COP Includes index. St. Paul, Minn. : West Pub. Co., c1984. c1984. 1984 Text xiii, 627, [60] p. : eng