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Math Help - Locous Question

  1. #1
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    Locous Question

    Find the locous of the intersection of tangents at R, given
    P (2ap, ap^2) and Q (2aq, aq^2) are points on 4ay = x^2

    Given that tangents are y = px - ap^2 and y = qx - aq^2

    and PQ is a focal chord, passing through (0,a) meaning pq = -1

    The point of intersection R is (a(p+q), apq)

    is the locus y = -a ? or is it different, as in y = qx/ (1-q^2) as suggested by an answer?
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  2. #2
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    y = –a is the correct solution. The other suggested solution does not work, because that equation is not satisfied by the coordinates of R.
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