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Discussion Response Post to: problem on parabola

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anchit saini (4396)

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$\mbox{Point of intersection of normals (y) =}-at_1t_2(t_1 + t_2) \\ \\ =-a \ \mbox{given as it lies on y=-a} \\ \\ \mbox{Hence , }t_1t_2(t_1 + t_2)=1 \\ \\ \mbox{Also,pt of intersection of tangents is }-> \\ \\ x= at_1t_2 \\ \\ y= a(t_1 + t_2) \\ \\ Thus, -> xy=a^2t_1t_2(t_1 + t_2)=a^2$