buktikan identitas trigonometri berikut (1-sin²y)² + (1-cos²y)² = 1-2 sin²y cos²y Kalo bisa pake coret2 an di kertas biar mudah dipahami

(1 - sin² y)² + (1 - cos² y)² = 1 - 2sin²y cos²y
(cos²y)² + (sin²y)² = 1 - 2sin²y cos²y
(sin²y)² + 2sin²y cos²y + (cos²y)² = 1
-->
(sin²y + cos²y)² = 1
1² = 1
1 = 1

terbukti

ini nih jawabannya maaf ya kalo salah