Trigonometry refresher 三角学重温

This classic text encompasses the most important aspects of plane and spherical trigonometry in a question-and-answer format, lts913 specially selected questions appear with detailed answers that help readers refresh their trigonometry skills or clear up difficulties in particular areas.
　　The first part discusses plane trigonometry, covering angles, quadrants, trigonometric functions, graphical representations, interpolation, equations, logarithms, solution of triangles, and similar topics. Questions and answers in the middle section discuss the application of plane trigonometry to special problems in navigation, surveying, elasticity, architecture, and various fields of engineering. Small angles, periodic functions, vectors, polar coordinates, and De Moivre's theorem receive full treatments. The third and final section explores spherical trigonometry and the solution of spherical triangles, with applications to terrestrial and astronomical problems.
　　Suitable for use as an undergraduate text, Trigonometry Refresher also features time-saving methods for numerical calculations, a simplified approach to the principal functions of an angle by use of a "shadow and perpendicular" concept, and several other practical aids—including 1,738 problems, many with solutions.

PREFACE
SECTION　Ⅰ　PLANE. TRIGONOMETRY
　CHAPTER
　 ANGLES AND THEIR MEASUREMENT
　 RELATIONSHIPS OF ANGULAR MEASUREMENTS
　 CARTESIAN COORDINATES--QUADRANTS
　 FUNDAMENTAL TRIGONOMETRIC FUOCTIONS
　 RELATED ANGLES
　 FUNCTIONS OF CERTAIN ANGLES
　 GRAPHICAL　REPRESENTATION　OF　FUNCTIONS--PERIODICITY
　 FUNDAMENTAL　IDENTITIES--IMPORTANT　RELA-TIONS OF ANALYTICAL TRIGONOMETRY OF FRE-QUENT OCCURRENCE
　 INTERPOLATION--BAsICIPRINCIPAL AND GENERAL ANGLES--INVERSE-FUNCTION NOTATION
　 TRIGONOMETRIC EQUATIONS
　 LOGARITHMS
　 SIGNIFICANT FIGURES--AccuRACY IN COMPUTA-
　 TIONS
　 SLIDE RULE
　 SOLUTION OF TRIANGLES
SECTION　Ⅱ　APPLICATIONS　OF　PLANE　TRIGONOMETRY
SMALL ANGLES
PERIODIC FUNCTIONS
VECTORS AND VECTOR QUANTITIES
DISTANcE--ANGULAR MEASUREMENT---SuRvEYING
NAVIGATION
MISCELLANEOUS PROBLEMS
POLAR　COORDINATES- COMPLEX　NUMBERS-DE MOIVRE'S THEOREM--SERIES
SECTION　Ⅲ　SPHERICAL　TRIGONOMETRY
　INTRODUCTION
　SPHERICAL TRIANGLES
　APPLICATIONS OF SPHERICAL TRIGONOMETRY
APPENDIX
　Customary definitions of the trigonometric functions of an acute angle
　Formulas used in the text Tables
ANSWERS TO 0DD-NUMBERED PROBLEMS
INDEX