cara membuktikan (sin 270°+Alfa)+cos(180°+Alfa)+cos alfa-sin(270°+Alfa)=0

Halo Antonius, kakak bantu jawab ya :) Jawaban dari pertanyaan di atas adalah terbukti bahwa (sin 270° + α) + cos(180° + α) + cos α - sin(270° + α) = 0. Sudut berelasi. Kuadran III (180° < α < 270°) sin (180° + α) = -sin α cos (180° + α) = -cos α tan (180° + α) = tan α Kuadran IV (270° < α < 360°) sin (270° + α) = -cos α cos (270° + α) = sin α tan (270° + α) = -cotan α Bukti (sin 270° + α) + cos(180° + α) + cos α - sin(270° + α) = 0 (sin 270° + α) + cos(180° + α) + cos α - sin(270° + α) = -cos α + (-cos α) + cos α - (-cos α) = -cos α - cos α + cos α + cos α = 0 Jadi terbukti bahwa (sin 270° + α) + cos(180° + α) + cos α - sin(270° + α) = 0. Semoga mmebantu ya, semangat belajar :)