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Re: Sections (was: One of my favourite pastimes ....)

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Archimedes Plutonium <plutonium.archimedes@gmail.com> writes:

>Alan you have no logical brains

You should talk, Illogical One.

If you really think an ellipse isn't a conic section, why can't you
either provide an actual proof, or disprove the following:


Some preliminaries:

Top view of the conic section and depiction of the coordinate system used 
in the proof:

              ^ x
              |
             -+- <= x=h
         .'   |   `.
        .     |     .
        |     |     |
        '     |     '      
         `.   |   .'
 y <----------+ <= x=0
             
Cone (side view):
                 .
                /|\
               / | \
              /b |  \
             /---+---' <= x = h
            /    |'   \
           /   ' |     \
          / '    |      \
x = 0 => '-------+-------\
        /    a   |        \

Proof:

r(x) = a - ((a-b)/h)x  and  d(x) = a - ((a+b)/h)x,  hence

y(x)^2 = r(x)^2 - d(x)^2 = ab - ab(2x/h - 1)^2 = ab(1 - 4(x - h/2)^2/h^2.

Hence (1/ab)y(x)^2 + (4/h^2)(x - h/2)^2 = 1  ...equation of an ellipse

qed


>A cow is a horse is a canary

>Get out of math-- it is over your head

You are the one who seems to think a cow is a canary.

(Yes, that's _probably_ satire, but given some of the bizarre things you
believe, I can never be certain...)

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One of my favourite pastimes is to rip out the arsehole of Graham-- and hand him back-- a brand new arsehole Archimedes Plutonium <plutonium.archimedes@gmail.com> - 2018-05-10 09:31 -0700
  Re: One of my favourite pastimes is to rip out the arsehole of Graham-- and hand him back-- a brand new arsehole grahamcooper7@gmail.com - 2018-05-10 09:51 -0700
    Re: One of my favourite pastimes is to rip out the arsehole of Graham-- and hand him back-- a brand new arsehole Archimedes Plutonium <plutonium.archimedes@gmail.com> - 2018-05-11 05:48 -0700
      Sections (was: One of my favourite pastimes ....) Alan Mackenzie <acm@muc.de> - 2018-05-11 15:02 +0000
        Sections (was: One of my favourite pastimes ....) Archimedes Plutonium <plutonium.archimedes@gmail.com> - 2018-05-11 08:59 -0700
          Re: Sections (was: One of my favourite pastimes ....) Alan Mackenzie <acm@muc.de> - 2018-05-11 16:23 +0000
          Re: Sections (was: One of my favourite pastimes ....) moroney@world.std.spaamtrap.com (Michael Moroney) - 2018-05-11 19:28 +0000

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