Madhava of Kerala discovered infinite power series expansions for trigonometric functions like sine, cosine, and arctangent in the 14th century, over 250 years before similar discoveries were made in Europe. These include the Madhava-Gregory series for pi and the Madhava-Newton power series for sine and cosine. Madhava founded the influential Kerala school of astronomy and mathematics. Several historians and mathematicians are quoted praising the significance and innovation of Madhava's work, though it went undiscovered by Western scholars for many years.