Indian mathematician and astronomer, b. 1114 (Biddur, India), d. c. 1185 (Ujjain ?).
Bhaskara II, or Bhaskara the Learned, was the director of India's leading centre of mathematics at the astronomical observatory in Ujjain. He was the first scientist to make full use of the Indian place-value number system. The title of his work Bijaganita ("Seed Counting") indicates his fascination with the possibilities of that number system. (see Lecture 6 for more detail on the Indian number system.)
Bhaskara returned to many of the problems discussed by Brahmagupta. He showed easier ways to handle them and tied up many loose ends in Brahmagupta's work. His writings are the first documents known today that discuss the problem of dividing through zero.* He introduced the use of symbols (letters) for unknowns in equations and gave solutions to various types of equations.
Through the analysis of regular polygons Bhaskara approximated the circle, and by using a regular polygon with 384 sides he derived the value 3.141666 for the irrational number p.
Two other of his works, Siddhantasiromani ("Head Jewel of Accuracy") and Karanakutuhala ("Calculation of Astronomical Wonders"), deal with astronomical observations and instruments.
Though a great scientist, Bhaskara was affected by the general decline of rational thought and tried his hand in astrology. Legend has it that his daughter was deprived of her only chance of marriage because she followed his astrological advice, and that he named his first work Lilavati after her in an attempt to console her. If true, it must be the only mathematical work that tried to make up for a missed happy marriage.
* In mathematics division through zero is an ill-defined operation, i.e it does not lead to an unambiguous result. Bhaskara II did not recognize this in all its aspects but tried to analyze what happens if a number is divided by zero. He states that the result is infinite.