In mathematics, the trigonometric functions (also called the circular functions) are functions of an angle. They relate the angles of a triangle to the lengths of its sides. Trigonometric functions are important in the study of triangles and modeling periodic phenomena, among many other applications.
Yellow stool is typically due to an excess of fatty foods and grease in the diet. Mayo Clinic states that it can also be caused by a malabsorption disorder such as celiac disease.
Bile is a normal product that is produced by your body. It can occur due to an infection, dehydration or another problem. Bright yellow bile is often produced early in the morning, but it does not have to be a sign of a major concern.