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A piece of wire 16 m long is cut into two pieces. One piece is bent into a square and the other is bent into a circle. How much wire should be used for the square in order to maximize the total area? How much wire should be used for the square in order to minimize the total area?

User Volni
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The minimize the total area, you should use 0 meters of wire for the square and use all 16 meters for the circle.

Maximizing Total Area:

1. Define the variables:

Let x be the length of the wire used for the square.

Then, the length of the wire used for the circle is 16 - x.

2. Formulate the area equations:

Area of the square: A_s = x^2 / 4

Area of the circle: A_c = πr^2, where r is the radius of the circle.

3. Relate the variables:

The circumference of the circle is equal to the perimeter of the square: 4x = 2πr.

Solve for r: r = 2x / π.

4. Substitute r in the area equation for the circle:

A_c = π(2x/π)^2 = 4x^2 / π

5. Formulate the total area equation:

Total area: A_t = A_s + A_c = x^2 / 4 + 4x^2 / π

6. Find the maximum total area:

Take the derivative of A_t with respect to x and set it equal to zero: dA_t/dx = (x / 2) - (8x / π) = 0.

Solve for x: x = 4π / 3.

Verify that it's a maximum by checking the second derivative.

7. Use the value of x to find the length for the square:

Square wire length: x = 4π / 3 = 4.19 m (approximately).

Therefore, to maximize the total area, you should use approximately 4.19 meters of wire for the square.

Minimizing Total Area:

1. Define the variables:

Use the same definitions as above.

2. Formulate the area equations:

Use the same equations as above.

3. Relate the variables:

Use the same equation as above.

4. Substitute r in the area equation for the circle:

Use the same equation as above.

5. Formulate the total area equation:

Use the same equation as above.

6. Find the minimum total area:

Since the quadratic term in A_t is always positive, the minimum total area occurs when x is minimized. Thus, you should use the minimum possible value for x, which is:

Minimum square wire length: x = 0 m.

Therefore, to minimize the total area, you should use 0 meters of wire for the square and use all 16 meters for the circle.

User Eswari
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