Brahmagupta was an Indian mathematician and astronomer who wrote the Bijaganita in the 7th century.

The Bijaganita was written in Sanskrit, the classical language of India.

The Bijaganita is a treatise on algebra, which is the branch of mathematics that deals with symbols and the rules for manipulating them.

The Bijaganita covers a wide range of algebraic topics, including linear equations, quadratic equations, cubic equations, and Diophantine equations.

Brahmagupta's formula for solving quadratic equations is $x = (-b \pm \sqrt{b^2 - 4ac}) / 2a$.

Brahmagupta's theorem on cyclic quadrilaterals states that the sum of the opposite angles of a cyclic quadrilateral is 180 degrees, the sum of the interior angles of a cyclic quadrilateral is 360 degrees, and the diagonals of a cyclic quadrilateral bisect each other.

Brahmagupta's identity is $a^2 + b^2 = (a + b)^2 - 2ab$.

Brahmagupta wrote an astronomical treatise called the Brahmasphutasiddhanta, which was a major work on astronomy and mathematics.

The Brahmasphutasiddhanta covers a wide range of astronomical topics, including the motion of the planets, the eclipses of the sun and moon, and the lunar mansions.

Brahmagupta used the epicyclic model to explain the motion of the planets.

Brahmagupta used the graphical method to calculate the eclipses of the sun and moon.

Brahmagupta's table of lunar mansions is a list of the 27 lunar mansions, which are the 27 divisions of the ecliptic.

Brahmagupta made significant contributions to the development of astronomy, including the development of the epicyclic model for the motion of the planets, the development of the graphical method for calculating the eclipses of the sun and moon, and the compilation of a table of lunar mansions.

The Bijaganita and the Brahmasphutasiddhanta are important historical documents, they contain important mathematical and astronomical knowledge, and they have influenced the development of mathematics and astronomy.

The Bijaganita and the Brahmasphutasiddhanta are two independent works, although they were both written by Brahmagupta.