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aleksandrvk [35]
3 years ago
6

A group of engineers is building a parabolic satellite dish whose shape will be formed by rotating the curve y=ax 2 about the y-

axis. If the dish is to have a 8-foot diameter and a maximum depth of 2 feet, find the value of a and the surface area (in square feet) of the dish. (Round the surface area to two decimal places.) What is the area and surface area?
Mathematics
1 answer:
Setler79 [48]3 years ago
6 0

Answer:

a = \frac{1}{2}. Surface Area = \frac{4}{3}ft^{2}. and area of the Dish = \frac{4}{3}ft^{2}+pi4^{2} = \frac{4}{3}ft^{2}+50.27=51.6ft^{2}

Step-by-step explanation:

(1) Constant. y(x) = ax^{2} that is the curve that we need to rotate around the y axis to get the parabola with diameter of 8 feet and 2 meter depth that statement is translated in mathematics as x = -4 to 4 and y = 0 to 2.

y max = 2, x max = 4 setting up a equation with a unknown gives

2=a4 and  a = \frac{1}{2}.

so we have now.

y(x) = \frac{1}{2}x^{2} (Done with solving for a Constant).

(2) Surface Area.

Setting Up surface integral.

(i) range in x = 0 to 4.

(ii) range in y = 0 to 2.

integral is.

Integral(0-2)[{integral[(0-4)\frac{1}{32}x^{2}]}]dy

Evaluating this integral gives. \frac{4}{3}ft^{2}.

and area is surface area + area of the circle with 8ft diameter.

= \frac{4}{3}ft^{2}+pi4^{2} = \frac{4}{3}ft^{2}+50.27=51.6ft^{2}...

Note the Difference between area and aurface area.!

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Question 5).

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