posted by Marissa .
A rectangle is inscribed with its base on the x axis and its upper corners on the parabola y= 12 - x^2. What are the dimensions of such a rectangle with the greatest possible area?
The vertices of the rectangle are points:
The area A(x)=2x(12-x^2)
A'(x)=24-6x^2=0 => x=+-2