jika tg A = 1/2 , nilai sin kuadrat 2 A adalah

Trigonometri

tan A = 1/2
misal
tan A = y/x
r² = x² + y²
r² = 2² + 1² = 5
r = √5

sin A = y/r = 1/√5
cos A = x/r = 2/√5
nilai sin² 2A = (sin 2A)² = ( 2 sin A  cos A)² = {(2)(1/√5 )( 2/√5)}²
sin² 2A = (4/5)² = 16/25