−1≤x2−2x−22≤1
x2−2x−21+x2−2x−2≥0
⇒(x−1)2−3(x−1)2−2≥0
⇒(x−1−3)(x−1+3)(x−1−2)(x−1+2)≥0
x∈(−∞,1−3)∪[1−2,1+2]∪(1+3,0)
1−x2−2x−21≥0⇒x2−2x−2x2−2x−3≥0
⇒(x−1+3)(x−1−3)(x+1)(x−3)≥0
x∈(−∞,−1]∪(1−3,3+1)∪[3,∞)∩(2)
⇒x∈(−∞,−1]∪[1−2,1+2]∪[3,∞)
∴α+β+γ+δ=4