sydney grammar 2009 trial question please help (1 Viewer)

jfanny123

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does any1 have the solutions for sydney grammar 2009 extension 2 trial solutions
realli stuck on question 7 part c iii

if anyone got solutions please help thanks heaps in advance
 

shaon0

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does any1 have the solutions for sydney grammar 2009 extension 2 trial solutions
realli stuck on question 7 part c iii

if anyone got solutions please help thanks heaps in advance
The point P is on the parabola, and you know the distance from P to directrix and P to focus is the same by PS=PM. Thus, there's a 2nd circle that passes via focus and is tangent to directrix which has P as it's centre. Cince, there's only one way possible for P, the two circle's must intersect at S. Thus, the two circles have the common tangent at S which is perpendicular to the radii (by circle geo property) ie O,S,P are collinear which means OP is the chord which passes via the focus.
 

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