1. Tentukan nilai sinus, cosinus, dan tangen untuk sudut P dan R pada setiap segitiga siku-siku di bawah ini. Nyatakan jawaban kamu dalam bentuk paling sederhana.
a)
PR = √(QP2 + QR2
= √(4^2 + 8^2)
= √(16 + 64) = √80 = 4√5
sin P = depan / miring = QR / PR = 8 / (4√5) = 2/√5
cos P = samping / miring = QP / PR = 4 / (4√5) = 1/√5
tan P = depan / samping = QR / QP = 8 / 4 = 2
sin R = depan / miring = QP / PR = 4 / (4√5) = 1/√5
cos R = samping / miring = QR / PR = 8 / (4√5) = 2/√5
tan R = depan / samping = QP / QR = 4 / 8 = 1/2
b)
PQ = √(PR2 – QR2)
= √(11^2 – 7^2)
= √(121 – 49) = √72 = 6√2
sin P = depan / miring = QR / PR = 7/11
cos P = samping / miring = PQ / PR = 6√2/11
tan P = depan / samping = QR / PQ = 7/6√2
sin R = depan / miring = PQ / PR = 6√2/11
cos R = samping / miring = QR / PR = 7/11
tan R = depan / samping = PQ / QR = 6√2/7
c)
PR = √(PQ2 + QR2)
= √(1^2 + 2^2)
= √(1 + 4) = √5
sin P = depan / miring = QR / PR = 2/√5
cos P = samping / miring = PQ / PR = 1/√5
tan P = depan / samping = QR / PQ = 2/1 = 2
sin R = depan / miring = PQ / PR = 1/√5
cos R = samping / miring = QR / PR = 2/√5
tan R = depan / samping = PQ / QR = 1/2