Mathematics · 2019
JEE Main · 10 January 2019, Shift 1 · Q81
If the parabolas y^2=4 b (x- c ) and y^2=8 a x have a common normal, then which one of the following is a valid choice for the ordered triad (a, b,…
If the parabolas $\displaystyle y^2=4 \mathrm{~b}(x-\mathrm{c})$ and $\displaystyle y^2=8 \mathrm{a} x$ have a common normal, then which one of the following is a valid choice for the ordered triad (a, b, c) ?
Official answer
(1)
$\displaystyle \left(\frac{1}{2}, 2,0\right)$
(2)
$\displaystyle (1,1,3)$
(3)
$\displaystyle (1,1,0)$
(4)
$\displaystyle \left(\frac{1}{2}, 2,3\right)$
NTA’s answer key accepts any one of these.
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JEE Main 2019 Mathematics question, with the answer from NTA’s final answer key. Where our answers come from.