Answer:
Option C
Explanation:
Let the normal at 't1' cuts the parabola again at the point 't2' , the equation of the normal at ( at21,2at1) is y+t1 x =2at1 +at13
Since it passes through the point 't2' i.e,
( at22,2at1)
∴ 2at2+at1t22=2at1+at31
⇒2a(t1−t2)+at1(t21−t22)=0
⇒2+t1(t1+t2)=0(∵t1−t2≠0)
⇒2+t21+t1t2=0
⇒t1t2=−(t21+2)⇒t2=−(t1+2t1)