Determine the equation of a circle whose diameter has the endpoints (–1, 2) and (7, –4). 1) (x – 3)2 + (y + 1)2 = 100
2) (x – 3)2 + (y + 1)2 = 5
3) (x – 3)2 + (y + 1)2 = 25
4) (x – 3)2 + (y + 1)2 = 10

Technicians have installed a center pivot, circular irrigator for a farm that covers 25 acres. a.) how long is the irrigation boom (in feet) from the center pivot to its farthest extent? b.) if the irrigation boom makes 4 full revolutions in a day, how many miles does the end of the boom travel in 5 days?