originally posted in:Secular Sevens
I'm going to assume it's an elliptic paraboloid, it should be easy to find the focus of the satellite dish?
English
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Edited by Ninja Guardian: 11/26/2013 6:01:14 AMUh yeah I don't know how. The professor was rushing through her material because we're behind schedule so she didn't go over any applications involving ellipses, or parabolas.
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I'm just going to think about it as a 2D problem by taking a cross section of the paraboloid. Well, let's place the origin at the vertex of the parabola, given that it rises 2 feet when you go across 8 feet, we know that the equation is: y = 1/32*(x^2) in two dimensions. The focus of the parabola will lie along the axis of symmetry, so x = 0. The y coordinate of the focus is found by arcane magics and equals (1-(b^2-4*a*c))/(4*a), but since the discriminant is 0, it is (1/4*a) which is (8). So if we place the origin at the vertex, the focus needs to be at coordinates (0,8) or alternatively, 8 feet above the vertex of the paraboloid/parabola. (Check with other people, not 100% sure if this is right).
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Actually scratch that, 32 wasn't the right answer 8 was. I was wondering why 32 was the answer when a receiver being placed 32 feet above a satellite that's 16 feet wide and 2 feet deep didn't make sense.
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Edited by Ninja Guardian: 11/26/2013 6:19:57 AMHuh, someone else in the thread said 32 feet. Okay, 32 feet was the correct answer. Thanks for trying to help though.