Question

Yang nomor delapanyan saja

Answer 1

Verified answer

Kelas 11 Matematika
Bab Trigonometri Lanjut

θ = p

2 cos² p = 1 + 2 sin 2p
2 cos² p - 1 = 2 sin 2p
cos 2p = 2 sin 2p
1/2 = sin 2p/cos 2p
tan 2p = 1/2
(2 tan p)/(1 - tan² p) = 1/2
2 . 2 tan p = 1 - tan² p
tan² p + 4 tan p - 1 = 0
a = 1; b = 4; c = -1

dengan rumus ABC
= (-b +- √(b² - 4ac))/(2 . a)
= (-4 +- √(4² - 4 . 1 . (-1)))/(2 . 1)
= (-4 +- √(16 + 4))/2
= (-4 +- √20)/2
= (-4 +- 2 √5)/2
= -2 +- √5

tan p = -2 + √5
tan P = √5 - 2

atau

tan p = -2 - √5

✩✩ D ✩✩