Tolong dijawab pakai caranya ya please, secepatnya

π = 180
4) sin (½π + x) = sin (½(180) + x)
= sin (90 + x)
= -cos x
5) √2 + 2.cos x = 0
2.cos x = -√2
cos x = -√2/2
cos x = -½√2
cos x = cos 135
x = 135
cos x = cos 225
x = 225
x1 + x2 = 135 + 225 = 360