The ancient mathematical and astronomical text 'Siddhanta Shiromani' was written by:

The "Siddhanta Shiromani" ("Crown of Treatises") was written by the great Indian mathematician and astronomer Bhaskaracharya (Bhaskara II) in 1150 CE.

About Bhaskaracharya:

• He was born in 1114 CE, probably at Vijjadavida (believed to be near Bijapur in Karnataka, or in Maharashtra), and died around 1185 CE.
• He was the head of the astronomical observatory at Ujjain, continuing the tradition of Varahamihira and Brahmagupta.
• He is regarded as one of the greatest mathematicians of medieval India.

Parts of the Siddhanta Shiromani:

It has four parts:

• "Lilavati": arithmetic, measurement and elementary geometry.
• "Bijaganita": algebra.
• "Grahaganita": mathematical astronomy (the motions of planets).
• "Goladhyaya": astronomy of the sphere (the celestial globe).

About Lilavati:

• According to legend, it was named after his daughter Lilavati; he wrote it to teach her mathematics.
• It contains many problems written in poetic form, often addressed to a girl.

His contributions:

• He worked on the concept of zero and infinity, and stated that any number divided by zero is infinite ("khahara").
• He gave methods to solve quadratic and indeterminate equations, including the "chakravala" method (cyclic method) to solve equations of the form Nx2 + 1 = y2 (later called Pell's equation).
• He developed early ideas of calculus, such as the instantaneous motion of planets, and something similar to the derivative.
• He described gravity, saying that the earth attracts objects towards itself.
• He calculated the time taken by the Earth to orbit the Sun accurately.

Honours:

India's second satellite, launched in 1979, was named "Bhaskara" (after Bhaskara I or II).

Other Indian mathematicians:

• "Aryabhata" (5th century): Aryabhatiya.
• "Brahmagupta" (7th century): Brahmasphutasiddhanta; rules for zero.
• "Varahamihira" (6th century): Panchasiddhantika.
• "Bhaskara I" (7th century): a commentator on Aryabhata.

Why not the other options?

• ✗Aryabhata, Brahmagupta and Varahamihira lived earlier and wrote other works.