Exteme values 3_1
1. Insert P(x) = x sqrt(4r² - x²) and press on the Enter key to draw the area of the carpet P as a function of side a
2. Insert P'(x)=Derivative(P) to draw the first derivative of the function
3. Notice that when a=b (the x-coordinate of the point Extreme) the area of the carpet is largest (the y-coordinate of the point Extreme)