Question
The normals at two points $\mathrm{P}$ and $\mathrm{Q}$ on the parabola $\mathrm{y}^{2}=4 \mathrm{ax}$ meet at a point $\mathrm{R}\left(\mathrm{x}_{1}, \mathrm{y}_{1}\right)$ on the parabola then $\mathrm{PQ}^{2}$ is(a) $\left(x_{1}-8 a\right)^{2}$(b) $\left(x_{1}-8 a\right)\left(x_{1}+4 a\right)$(c) $\left(x_{1}-4 a\right)\left(x_{1}+8 a\right)$(d) $x_{1}^{2}-16 a^{2}$
Step 1
The equation of the normal at any point $(at^{2},2at)$ on the parabola is given by $y=tx-2at-at^{3}$. Therefore, the equations of the normals at P and Q are $y=t_{1}x-2at_{1}-at_{1}^{3}$ and $y=t_{2}x-2at_{2}-at_{2}^{3}$ respectively. Show more…
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Nonlinear Systems of Equations
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