ya , ▁the ▁mighty ▁Mag ad h ▁Empire ▁had ▁become ▁the ▁most ▁powerful , ▁most ▁influ ential , ▁most ▁developed ▁and ▁the ▁rich est ▁emp ire ▁of ▁the ▁world , ▁and ▁P atal i put ra ▁had ▁become ▁the ▁most ▁beautiful ▁city . ▁ ▁After ▁ 5 th ▁century ▁AD , ▁K us ump ur ▁was ▁renamed ▁as ▁Kh aga ul ▁after ▁Kh ag ol ▁or ▁Kh ag ol ▁Sh ast ra ▁i . e . ▁Astronom y , ▁as ▁it ▁was ▁an ▁em inent ▁centre ▁of ▁Astronom ical ▁Observ atory ▁( K h ag oli ya ▁V ed hash ala ) ▁established ▁by ▁A ry ab h ata ▁or ▁A ry ab hat ta ▁for ▁Astronom ical ▁Studies ▁and ▁Astronom ical ▁Research . ▁A ry ab hat ta ▁is ▁called ▁Father ▁of ▁Al gebra , ▁Ge ometry ▁and ▁Tr ig on ometry , ▁Con cept ▁of ▁Zero ▁( 0 ) ▁and ▁decimal ▁system . ▁ ▁A ry ab h ata , ▁also ▁called ▁A ry ab h ata ▁I ▁or ▁A ry ab h ata ▁the ▁E lder ▁▁ ▁( born ▁in ▁the ▁year ▁ 4 7 6 ▁AD , ▁at ▁K us um ap ura , ▁near ▁P atal i put ra ▁or ▁present ▁day ▁Pat na ▁in ▁India ) ▁was ▁astronom er ▁and ▁the ▁earliest ▁Indian ▁math ematic ian ▁whose ▁work ▁and ▁history ▁are ▁available ▁to ▁modern ▁sch ol ars . ▁He ▁is ▁also ▁known ▁as ▁A ry ab h ata ▁I ▁or ▁A ry ab h ata ▁the ▁E