(1) [√(1-2sin50°cos50°)]/cos50°+√(1-sin²220°)
=[√(sin²50°+cos²50°-2sin50°cos50°)]/cos50°+√(cos²220°)
=[√(sin50°-cos50°)²]/cos50°+√(cos²220°)
=|sin50°-cos50°|/cos50°+|cos220°|
=(sin50°-cos50°)/cos50°+cos40°
=tan50°+cos40°-1
(2) sin(x+π/6)=cos[π/2-(x+π/6)]
=cos(π/3-x)
=cos(x-π/3)
=√7/5