The correct option is C t1t2=2
Normal at point P(t1) meets the parabola again at point R(t3), then
t3=−t1−2t1
Also normal at point Q(t2) meets the parabola at the same point R(t3), then
t3=−t2−2t2
Comparing these values of t3, we have
−t1−2t1=−t2−2t2
⇒t1t2=2