tlg bantu no 11 ya tk tggu☺☺

tan a = -1/2 kuadran 4
sisi depan 1
sisi samping 2
sisi miring √5
sin a = -1/√5
cos a = 2/√5

2 cos A - sin A
= 2 (2/√5) - (-1/√5)
= 4/√5 + 1/√5
= 5/√5 ×√5/√5
= (5/5)√5
= √5