Jawabanmu

2014-03-19T06:12:08+07:00
2sin²(x) - 7sin(x) + 3 = 0
(2sin(x) - 1) (sin(x) - 3) = 0


2sin(x) - 1 = 0
2sin(x) = 1
sin(x) = 1/2
x = 30
° atau 150°


sin(x) - 3 = 0
sin(x) = 3
x = ga ada di sudut istimewa -_-


syaratnya tadi, x ada di kuadran I. jadi x = 30°, maka
cos(x)
= cos(30)
°
= 1/2 
√3
1 4 1