Śrīdhara,^[1] also known as Sridhar Acharya, or Śrīdharācāryya (c. 870 CE – c. 930 CE) was a mathematician, Sanskrit pandit and philosopher from the Bengal region of ancient India. He was born in a village called Bhuriśreṣṭi (Bhurisriṣṭi or Bhurśuṭ), which is now part of Hugli in West Bengal, then undivided Bengal with its capital at Gaur. His father, Baladeva Acharya or Baladevācārya, was a Sanskrit pandit, and his mother's name was Acchoka Devi.

Notable work

He is known for two main treatises: Pāṭīgaṇitasāra (also called Triśatika (300) because it was written in three hundred ślokas) and Pāṭīgaṇita (Bengali: পাটীগণিত). Triśatika discusses counting of numbers, natural number, zero, measures, multiplication, fraction, division, squares, cubes, rule of three, interest-calculation, joint business or partnership, and mensuration (the main part of geometry concerned with ascertaining sizes, lengths, areas, and volumes).

Three other works have been attributed to him, namely the Bījaganita, Navasatī, and Bṛhatpati. Some historians believe that Sridhara may have authored another mathematical treatise called Gaṇitapañcaviṃśi.^[2]

His notable work includes:^[3]

• He gave an exposition on the zero. He wrote, "If zero is added to any number, the sum is the same number; if zero is subtracted from any number, the number remains unchanged; if zero is multiplied by any number, the product is zero".
• In the case of dividing a fraction he has found out the method of multiplying the fraction by the reciprocal of the divisor.
• He wrote on the practical applications of algebra.
• He separated algebra from arithmetic.
• He was one of the first to give an algorithm for solving quadratic equations (although there is no indication that he considered two solutions). The modern-day quadratic formula is called Sridharacharya's Formula or Sridharacharya's Method in some places. The solution to a quadratic equation of the general form ax² + bx + c = 0, a ≠ 0 is given by

${\displaystyle x={\frac {-b\pm {\sqrt {b^{2}-4ac}}}{2a}}}$

References

Bibliography

• O'Connor, John J.; Robertson, Edmund F., "Sridhara", MacTutor History of Mathematics Archive, University of St Andrews
• The Date of Sridharacharya by S. Srikanta Sastri, The Jaina Antiquary (Jan, 1948)