Question

A rope 16 feet long is cut into two pieces. one piece is used to form a circle and the other used to form a square. find a function representing the area of both square and circle as a function of the length of one side of the square.

Answer 1

Circumference of Circle=C, =2(pi)(radius)
Radius of Circle=r
Side of square=x
f(x)=area of circle
g(r)=area of square
16 feet=C+4x
C=16-4x
2(pi)(r)=16-4x
2(pi)(r)=2(8-2x)
(pi)(r)=8-2x
r=(8-2x)/(pi)
x=(8-(pi)r)/2
f(x)=(pi)(r^2)
f(x)=(pi)((8-2x)/(pi))^2
f(x)=((8-2x)^2)/(pi)
f(x)=((64-32x+4x^2))/(pi)
g(r)=((8-(pi)r)/2)^2
g(r)=((64-16(pi)r+(pi)^2(r^2))/4