Bhāskara II also known as Bhāskarāchārya or "Bhāskara the teacher" is an Indian mathematician and astronomer.
his works represent a significant contribution to mathematical and astronomical knowledge in the 12th century. He has been called the greatest mathematician of medieval India.
Bhāskara II (1114–1185) is credited with knowledge of Rolle's theorem.
His main work Siddhānta Shiromani, (Sanskrit for "Crown of Treatises") is divided into four parts called Lilāvatī,
Bījagaṇita , Grahagaṇita and Golādhyāya,  we will be discussing only a few part of his work.

Bhāskara's work on calculus predates Newton and Leibniz by over half a millennium.
He is particularly known in the discovery of the principles of differential calculus and its application to astronomical problems and computations. While Newton and Leibniz have been credited with differential and integral calculus, there is strong evidence to suggest that Bhāskara was a pioneer in some of the principles of differential calculus. He was perhaps the first to conceive the differential coefficient and differential calculus.

Bhaskara's arithmetic text Leelavati covers the topics of definitions, arithmetical terms, interest computation, arithmetical and geometrical progressions, plane geometry , solid geometry , the shadow of the gnomon, methods to solve
indeterminate equations, and
combinations .
Lilavati is divided into 13 chapters and covers many branches of mathematics, arithmetic, algebra, geometry, and a little trigonometry and measurement.
His Bijaganita ("Algebra ") was a work in twelve chapters. It was the first text to recognize that a positive number has two square roots (a positive and negative square root).

     The Siddhānta Shiromani (written in 1150) demonstrates Bhaskara's knowledge of trigonometry, including the sine table and relationships between different trigonometric functions. He also discovered
spherical trigonometry , along with other interesting trigonometrical results. In particular Bhaskara seemed more interested in trigonometry for its own sake than his predecessors who saw it only as a tool for calculation. Among the many interesting results given by Bhaskara, discoveries first found in his works include computation of sines of angles of 18 and 36 degrees.
    His work, the Siddhānta Shiromani , is an astronomical treatise and contains many theories not found in earlier works.
Preliminary concepts of infinitesimal calculus and
mathematical analysis , along with a number of results in trigonometry ,
differential calculus and integral calculus that are found in the work are of particular interest.
Evidence suggests Bhaskara was acquainted with some ideas of differential calculus. Bhaskara also goes deeper into the 'differential calculus' and suggests the differential coefficient vanishes at an extremum value of the function, indicating knowledge of the concept of infinitesimals.