If the domain of the function f(x)=sin-1(1x2-2x-2), is (-∞,α]∪[β,γ]∪[δ,∞), then α+β+γ+δ is equal to [2026]
(1)
-1≤2x2-2x-2≤1
1+x2-2x-2x2-2x-2≥0⇒(x-1)2-2(x-1)2-3≥0
⇒(x-1-2)(x-1+2)(x-1-3)(x-1+3)≥0
x∈(-∞,1-3)∪[1-2,1+2]∪(1+3,0) ...(1)
1-1x2-2x-2≥0⇒x2-2x-3x2-2x-2≥0
⇒(x+1)(x-3)(x-1-3)(x-1+3)≥0
x∈(-∞,-1]∪(1-3,1+3)∪[3,∞) ...(2)
(1)∩(2)
⇒x∈(-∞,-1]∪[1-2,1+2]∪[3,∞)
∴ α+β+γ+δ=4