Re: HSC 2016 3U Marathon
equation of pq = y=((p+q)/2)x - apq
For this to be a focal chord must pass through o,a
sub o,a --> a=-apq therefore pq=-1 (not too sure if this would count as proof that its a focal chord but if i recall the textbook states this is general form)
b)d(1/4a.x^2)/dx...