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.
Bilirubin concentration can vary the color of stool from light yellow to almost black. Changes in the chemical structure of the bilirubin can cause stool to turn green or yellow. Yellow stool also may occur if stool is dilute or there is a reduction in the amount of bilirubin that is produced by the liver. Bacteria and digestive enzymes in the intestine can act on the bilirubin and change its color. Most stool-to-stool changes in color have little meaning.