Chitrabhanu (;) was a mathematician of the Kerala school and a student of Nilakantha Somayaji. He was a Nambudiri brahmin from the town of Covvaram near present day Trissur.[1] He is noted for a, a concise astronomical manual, dated to 1530, an algebraic treatise, and a commentary on a poetic text. Nilakantha and he were both teachers of Shankara Variyar.[2]
He gave integer solutions to 21 types of systems of two simultaneous Diophantine equations in two unknowns.[3] These types are all the possible pairs of equations of the following seven forms:[4]
x+y=a,x-y=b,xy=c,x2+y2=d,x2-y2=e,x3+y3=f,x3-y3=g
For each case, Chitrabhanu gave an explanation and justification of his rule as well as an example. Some of his explanations are algebraic, while others are geometric.