A machinist is required to manufacture a circular metal disk with area 840 cm². Give your answers in exact form. Do not write them as decimal approximations. a) What radius, z, produces such a disk? b) If the machinist is allowed an error tolerance of ±5 cm² in the area of the disk, how close to the ideal radius in part (a) must the machinist control the radius? c) Using the e/o definition of a limit, determine each of the following values in this context: f(x)= = a= L= € = 8 =