Yudasril, Berlian Setiawaty, and I Gusti Putu Purnaba. 2022. “ifat emonotonan arisan rapezoid um ari elas ungsi onkonveks an onkonkaf”. imits: ournal of athematics and ts pplications 19 (1):49-63. https://journal.its.ac.id/index.php/limits/article/view/5346.