Question
Question: If AB makes 90<sup>0</sup> angle at the vertex of parabola then-...
If AB makes 900 angle at the vertex of parabola then-
A
t1t2 = – 1
B
t1t2 = – 4
C
t1 = t22
D
t2 = – t12
Answer
t1t2 = – 4
Explanation
Solution
q = 900 \slope of OA) (slope of OB) = – 1
2at1 – 0/at12 – 0 × 2at2 – 0/at22 – 0 = – 1
2/t1 × 2/t2 = – 1
\ t1t2 = – 4