“…Research exclusively -or mainly-focusing on the mathematical knowledge that is necessary for teaching the concept of function has been on the increase in recent years (Aziz, Pramudiani, & Purnomo, 2018;Aziz & Kurniasih, 2019;Malambo, Van Putten, Botha, & Stols, 2019;McCulloch, Lovett, & Edgington, 2019;Lovett & Edgington, 2019;Paoletti, Stevens, Hobson, Moore, & LaForest, 2018;Sintema, Phiri, &Marbán, 2018;Taşdan, 2019;Ubah & Bansilal, 2018). In the paper by Aziz et al(2018), the authors examined prospective secondary teachers' views regarding their knowledge of differences between functions and quadratic equations.…”