Question 1052889: A laboratory designed a radio telescope with a diameter of 380 feet and a maximum depth of 42 feet. The graph depicts a cross section of this telescope. Find the equation of this parabola.
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! A laboratory designed a radio telescope with a diameter of 380 feet and a maximum depth of 42 feet. The graph depicts a cross section of this telescope. Find the equation of this parabola.
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Points of the parabola:: (-190,0),(0,-42),(190,0)
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Form:: ax^2 + bx + c = y
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Using (0,-42) you get c = -42
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Using (-190,0):: 190^2a - 190b = +42
Using (190,0) :: 190^2a + 190b = 42
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2(190^2a) = 84
a = 0.0012
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Solve for "b"::
190b = 42 - 190^2*0012
190b = -1.32
b = -0.0069
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Equation:
y = 0.0012x^2 - 0.0069x -42 = 0
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Cheers,
Stan H.
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