Early Life and Work
Brahmagupta was an Indian mathematician, born in 598 AD in Bhinmal, a state of Rajhastan, India. He spent most of his life in Bhinmal which was under the rule of King Vyaghramukha. He was the head of the astronomical observatory at Ujjain which was the center of mathematics in India witnessing the work of many extraordinary mathematicians.
Brahmagupta wrote many textbooks for mathematics and astronomy while he was in Ujjain. These include ‘Durkeamynarda’ (672), ‘Khandakhadyaka’ (665), ‘Brahmasphutasiddhanta’ (628) and ‘Cadamakela’ (624). The ‘Brahmasphutasiddhanta’ meaning the ‘Corrected Treatise of Brahma’ is one of his well-known works. It contains a lot of criticism on the work of his rival mathematicians. Brahmagupta had many discrepancies with his fellow mathematicians and most of the chapters of this book talked about the loopholes in their theories.
Contributions to Mathematics
One of the most significant input of Brahmagupta to mathematics was the introduction of ‘zero’ to the number system which stood for ‘nothing’. His work the ‘Brahmasphutasiddhanta’ contained many mathematical findings written in verse form. It had many rules of arithmetic which is part of the mathematical solutions now. These are ‘A positive number multiplied by a positive number is positive.’, ‘A positive number multiplied by a negative number is negative’, ‘A negative number multiplied by a positive number is negative’ and ‘A negative number multiplied by a negative number is positive’. The book also consisted of many geometrical theories like the ‘Pythagorean Theorem’ for a right angle triangle. Brahmagupta was the one to give the area of a triangle and the important rules of trigonometry such as values of the sin function. He introduced the formula for cyclic quadrilaterals. He also gave the value of ‘Pi’ as square root ten to be accurate and 3 as the practical value. Additionally he introduced the concept of negative numbers.
Contribution to Science and Astronomy
Brahmagupta argued that the Earth and the universe are round and not flat. He was the first to use mathematics to predict the positions of the planets, the timings of the lunar and solar eclipses. Though all this seems like obvious and simple solutions it was a major improvement in science at that time. He also calculated the length of the solar year which was 365 days, 5 minutes and 19 seconds which is quite accurate based on today’s calculation of 365 days, 5 hours and 19 seconds. He also talked about ‘gravity’ in one of his statements saying: ‘Bodies fall towards the earth as it is in the nature of the earth to attract bodies, just as it is in the nature of water to flow’.
This great mathematician died between 660 and 670. He was one of the greatest mathematicians in Indian history and his contributions to mathematics and science have made major differences to various mathematical problems by establishing the basic rules which now allow us to find their solutions. He was honored by the title given to him by a fellow scientist ‘Ganita Chakra Chudamani’ which is translated as ‘The gem of the circle of mathematicians’.