contestada

Steve likes to entertain friends at parties with "wire tricks." Suppose he takes a piece of wire 56 inches long and cuts it into two pieces. Steve takes the first piece of wire and bends it into the shape of a perfect circle. He then proceeds to bend the second piece of wire into the shape of a perfect square. What should the lengths of the wires be so that the total area of the circle and square combined is as small as possible

Respuesta :

Answer:

Step-by-step explanation:

Let the length of first piece be L .

Length of second piece = 56 - L

radius of circle made from first piece

R = L / 2π

Area of circle = π R²

= L² / 4π

side of square made fro second piece

= (56 - L) / 4

area of square = ( 56-L)² / 16

Total area

A = L² / 4π + ( 56-L)² / 16

For smallest possible combined area

dA / dL = 0

dA / dL = 2L /  4π - 2( 56-L)/16 =0

2L /  4π = 2( 56-L)/16

.159 L = 7 - .125 L

.284 L = 7

L = 24.65 inch

other part = 56 - 24.65

= 31.35 inch .

Otras preguntas