Question

Group of engineers is building a parabolic satellite dish whose shape will be formed by rotating the curve y = ax2 about the y-axis. if the dish is to have a 10-ft diameter and a maximum depth of 4 ft, find the value of a and the surface area s of the dish. (round the surface area to two decimal places.)

Answer 1

10' diameter and maximum depth of 4', it means that the point (5,4) is on the profile of the dish.

Fitting in the given formula,

y=ax^2 => 4=a(5^2) => a=4/25