1)cos2x>= -0.5√2 2) x+y=pi/2 sinx+siny= -√2

Question

1)cos2x>= -0.5√2

2)
x+y=pi/2
sinx+siny= -√2

Answer 1

Sinx=1/2
x=(-1)^nπ6+πn
siny=-1/2
y=(-1)^(n+1)π/6+πn