Question

7 points!

jika cos x = 2 sin x, maka nilai sin x * cos x adalah

a 1/5
b 1/4
c 1/3
d 2/5
e 2/3

Answer 1

Trigonometri

cos x = 2 sin x
sin x/cos x = depan/samping = 1/2
r = √(d² + s²) = √(1² + 2²) = √5

sin x × cos x
= d/r × s/r
= 1/√5 × 2/√5
= 2/5 ✔