Chén Jìxīn 陳際新
An eighteenth-century Chinese mathematician who served as principal pupil and editorial successor of 安圖 Mínggatu (Ming’antu) at the imperial Bureau of Astronomy. Birth and death years not securely recorded; fl. mid-Qián-lóng. CBDB id 438186 confirms the name and dynasty.
Chén Jìxīn’s principal scholarly task was putting Mínggatu’s Gēyuán mìlǜ jiéfǎ 割圏密率捷法 (KR3fc037) — the great Chinese-language exposition of the European-derived trigonometric power-series — through final editing and publication after Mínggatu’s death in 1765. The work had been incomplete at Mínggatu’s death; Chén Jìxīn, drawing on his direct instruction by Mínggatu and on the working manuscript material left at the Bureau of Astronomy, completed the exposition, supplied missing derivations, and prepared the published 6-juàn text. The catalog records him as xù 續 (continuator) of the work.
Chén Jìxīn is also recorded as one of the principal Bureau-of-Astronomy mathematicians of the mid-Qián-lóng era; his other Bureau work — on the Yíxiàng kǎochéng and the supplementary calendrical compilations — is preserved without separate authorial attribution within the larger imperially-commissioned series.