According to The Orange Grove, "This book covers elementary trigonometry. It is suitable for a one-semester course at the college level, though it could also be used in high schools. The prerequisites are high school algebra and geometry. Contents: 1) Right Triangle Trigonometry. 2) General Triangles. 3) Identities. 4) Radian Measure. 5) Graphing and Inverse Functions. 6) Additional Topics. Appendix A) Answers and Hints to Selected Exercises. Appendix B) Graphing with Gnuplot."