Question

The tangent to the parabola `y^(2)=4ax` at `P(at_(1)^(2), 2at_(1))" and Q"(at_(2)^(2), 2at_(2))` intersect on its axis, them
A. `t_(1)=t_(2)`
B. `t_(1)=-t_(2)`
C. `t_(1)t_(2)=2`
D. `t_(1)t_(2)=-1`

Answer 1

Correct Answer - B
Tangents at P and Q intersect at `R(at_(1)t_(2),a(t_(1)+t_(2)))`. Since R lies at the axis of the parabola i.e. x-axis
`:." "a(t_(1)+t_(2))=0rArrt_(2)=-t_(2)`