(-∞,-3
∪
1,+∞)
设 P ( t , t 2-1), Q ( s , s 2-1)
∵ BP ⊥ PQ ,∴
=-1,
即 t 2+( s -1) t - s +1=0
∵ t ∈R,∴必须有 Δ =( s -1) 2+4( s -1)≥0. 即 s 2+2 s -3≥0,
解得 s ≤-3或 s ≥1.
(-∞,-3
∪
1,+∞)
设 P ( t , t 2-1), Q ( s , s 2-1)
∵ BP ⊥ PQ ,∴
=-1,
即 t 2+( s -1) t - s +1=0
∵ t ∈R,∴必须有 Δ =( s -1) 2+4( s -1)≥0. 即 s 2+2 s -3≥0,
解得 s ≤-3或 s ≥1.