(4 points) A machinist is required to manufacture a circular metal disk with area 1000 cm2 . (a) What radius produces such a disk? (b) If the machinist is allowed an error tolerance of ±5cm2 in the area of the disk, how close to the ideal radius in part (a) must the machinist control the radius? (c) In terms of the limit limx→a f(x) = L, what is f(x)? What is a? What is L?