If one end of a focal chord AB of the parabola y2 = 8x is at $A\left( {{1 \over 2}, - 2} \right)$, then the equation of the tangent to it at B is :
Solution
Given parabola y<sup>2</sup>
= 8x
<br><br> $\therefore$ a = 2
<br><br>Let one end of focal chord is A(at<sup>2</sup>
, 2at) = $\left( {{1 \over 2}, - 2} \right)$
<br><br>$\therefore$ 2at = -2
<br><br>$\Rightarrow$ t = $- {1 \over 2}$
<br><br>Other end of focal chord will be B$\left( {{a \over {{t^2}}}, - {{2a} \over t}} \right)$ $\equiv$ (8, 8)
<br><br>$\therefore$ Equation of tangent at B is
<br><br>8y = 4(x + 8)
<br><br>$\Rightarrow$ x – 2y + 8 = 0
About this question
Subject: Mathematics · Chapter: Conic Sections · Topic: Parabola
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