Question 1098711
Using the notation there, the square has area x^2 and the circle's area is f(radius), and the radius can be found by taking 10-4x, the circumference, and dividing by 2pi, so the area of the circle is pi*[(5-2x)/(pi)]^2, after reducing the radius to (5-2x)/pi
The sum of these areas is x^2+[pi*(5-2x)^2/pi^2]
Take the derivative and set equal to 0: 2x+(1/pi)(2(5-2x)(-2))=0

This is 2x + (1/pi)(4x-20)=0
multiply by pi
2x*pi+4x-20=0=x*pi+2x-10
x(pi+2)=10
x=10/(pi+2)
{{{graph(300,300,-8,8,-3,10,x^2+(5-2x)^2/pi)}}}
Minimum is when A=3.5 m^2 and x=1.4 m