>>497
(sinθ-cosθ)^2 = 1/3
1-2sinθcosθ = 1/3
2sinθcosθ = 2/3

(sinθ+cosθ)^2 = (sinθ-cosθ)^2 +4sinθcosθ = 5/3
sinθ+cosθ = ±√(5/3)