Question

3 cos x + sin x =3

Ubah bentuk a cos x + b sin x menjadi k cos (x-alpha)

Answer 1

cos x + √3 sin x = k . cos ( x - A)

a= -1 , b= √3

k = √(a² +b²)= √(1+3)=√4 ---> k = 2

tan A = b/a = √3/(-1) = - √3 , A di KD II

tan A = - √3 =  - tan 60 = tan(180-60) =tan 120

A = 120

k cos (x - A) = 2 cos (x - 120)

( mf klw salah)