Karanapaddhati is an astronomical treatise in Sanskrit attributed to Puthumana Somayaji, an astronomer-mathematician of the Kerala school of astronomy and mathematics.
Whish, a civil servant of the East India Company, brought this work to the attention of European scholars for the first time in a paper published in 1834.
The last verse of the tenth chapter of Karanapaddhati describes the author as a Brahamin residing in a village named Sivapura.
vargairyujāṃ vā dviguṇairnirekairvargīkṛtair-varjitayugmavargaiḥ vyāsaṃ ca ṣaḍghanaṃ vibhajet phalaṃ svaṃ vyāse trinīghne paridhistadā syāt
cāpācca tattat phalato'pi tadvat cāpāhatāddvayādihatat trimaurvyā labdhāni yugmāni phalānyadhodhaḥ cāpādayugmāni ca vistarārdhāt vinyasya coparyupari tyajet tat śeṣau bhūjākoṭiguṇau bhavetāṃ
vyāsārdhena hatādabhiṣṭaguṇataḥ koṭyāptamaādyaṃ phalaṃ jyāvargeṇa vinighnamādimaphalaṃ tattatphalaṃ cāharet kṛtyā koṭiguṇāsya tatra tu phaleṣvekatripañcādibhir- bhakteṣvojayutaistajet samajutiṃ jīvādhanuśiśaṣate
tan−1 x = x - x3 / 3 + x5 / 5 - ... Venketeswara Pai R, K Ramasubramanian, M S Sriram and M D Srinivas, Karanapaddhati of Putumana Somayaji, Translation with detailed Mathematical notes, Jointly Published by HBA (2017) and Springer (2018).