The term MATH COURSE WITH SINES AND TANS is a reference to the four-letter word TRIG, which stands for trigonometry. Trigonometry is a branch of mathematics that studies relationships between angles and sides of triangles, as well as the relationships between angles and lengths of arcs in circles. It is used to solve problems involving distances, heights, and angles of various shapes and figures. Trigonometry is often used in physics, engineering, and other sciences.