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.
But, see a doctor for evaluation. Yellow stool is unusual, and may be a symptom of a serious medical condition. Yellow stool can be caused by conditions that reduce pancreatic lipase production or that block its transport to the intestines.