Brahmagupta
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Area of a cyclic quadrilateral with side a,b,c,d = √(s‐a)(s‐b)(s‐c)(s‐d), where 2s= a+b+c+d. | Area of a cyclic quadrilateral with side a,b,c,d = √(s‐a)(s‐b)(s‐c)(s‐d), where 2s= a+b+c+d. | ||
| − | Length of its diagonals= √bc+ad/ √(ab+cd), √ab+cd/ √(bc+ad). | + | Length of its diagonals= {√bc+ad/ √(ab+cd)} (ac+bd), {√ab+cd/ √(bc+ad)} (ac+bd). |
Revision as of 08:52, 11 January 2018
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Who was Brahmagupta?
J.P.Bohre, NCERT- Contribution of Indian Mathematicians
(1) Brahmagupta was born in 598 A.D.in Bhinmal city in the state of Rajasthan. He was a mathematician and astronomer, who wrote many important works on mathematics and astronomy. His best known work is the “Brahmasphuta‐siddhanta”, written in 628 AD in Bhinmal.
(2) He was the first to use zero as a number. He gave rules to compute with zero.
(3) He gave four methods of multiplication.
(4) He gave following formulae, used in G.P. series
a+ar+ar2+ar3 +..........+arn‐1 =a(rn ‐1)/( r‐1)
(5) He gave the following formulae(Brahmagupta’s formula):
Area of a cyclic quadrilateral with side a,b,c,d = √(s‐a)(s‐b)(s‐c)(s‐d), where 2s= a+b+c+d.
Length of its diagonals= {√bc+ad/ √(ab+cd)} (ac+bd), {√ab+cd/ √(bc+ad)} (ac+bd).
