>>204
[Trivial]
x^2 - x/2 - 1/2 = (x+1/2)(x-1) = (x-α)(x-β),
(与式) = ∫[-1, α] (xx - x/2 - 1/2) dx + ∫[α,β] (β-x)(x-α) dx
　= [ (1/3)x^3 - (1/4)xx - (1/2)x ](x=-1,α) + (1/6)(β-α)^3　　(←公式)
　= 1/12 + 7/48 + 9/16
　= 19/24
　= 0.791667