Design of Proving Worksheet Based on APOS Theory on Trigonometric Functions of Sum and Difference of Two Angles - Ardiansyah, Hijir; Hartono, Yusuf; Darmawijoyo, Darmawijoyo (Kreano : Jurnal Matematika Kreatif-Inovatif, 2024)
Keywords: apos; lkpd; proof learning; sum and difference of two angles