Question

A piece of wire 10 m long is cut into two pieces. One piece is bent into a square and the other is bent into a circle. (Give your answers correct to two decimal places.) (a) How much wire should be used for the circle in order to maximize the total area? (b) How much wire should be used for the circle in order to minimize the total area?

I got the max but cant figure out the min... any help would be great. message and i'll let you kno what i do have so far...

Answer 1

do you have an equation relating the two?

Answer 2

and by two i mean the area of the square and the area of the circle

Answer 3

like the area of the circle would be the length aloted to it divided by pi squared times pi

Answer 4

and the square would be the length allotted to it divided by 4 squared

Answer 5

i know that the area of the circle A=pi(r^2) and the area of the square is s^2t. the sides are (10-x)/4 and the Area combined formula is pir^2+s^2

Answer 6

ok, also substitute x/pi for r

Answer 7

x/2pi

Answer 8

so instead of the combined area u have there, u have pi*(x/2pi)^2+((10-x)/4)^2

Answer 9

then derivative of tha?

Answer 10

*that

Answer 11

yea derive it and find where the derivative is equal to zero, substitute back in and u should have max and min (i hope)

Answer 12

i couldnt remembre what to sub in for r... THANKS!!

Answer 13

np