Question 744051
A satellite dish has a parabolic cross section and is 6 ft deep. The focus is 4 ft from the vertex. Find the width of the satellite dish at the opening. Round your answer to the nearest foot.
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place vertex at (0,0)
basic equation: x^2=4py
p=4 (distance from vertex to focus)
4p=16
equation: x^2=16y
y=6 at ends of parabolic cross section
x^2=16*6=96
x=±√96
width of the satellite dish at the opening=2*√96≈20 ft