Question

Bantuiin pakek caranya ya kak ?
bentuk (-cos x - √3 sin x ) dapat diubah dalam bentuk ?
a. 2 cos ( x - 4/3π)
b. -2 cos ( x + 4/3π)
c. 2cos(x+1/3π)
d. -2 cos ( x -7/6π)
e. 2cos(x-7/6π)

Answer 1

Bentuk berikut:
a.sin x + b.cos x = √(a²+b²)cos(x - tan⁻¹a/b)
Maka, dengna a = -√3 dan b = -1
Maka,
= √(-√3)²+(-1)²). cos(x - tan⁻¹ (-√3/-1))
= √3+1. cos(x - (π+π/3))
= √4. cos(x - 7π/3)
= 2.cos(x - 7π/3)
= -2.cos(x - 2π - π/3)
= -2.cos(x-π/3)
Alias:
= -2.[-cos(x - π/3 - π)] dengan [Pengurangan π]
= 2.cos(x - 4π/3) [A]