A line segment of length 5 has one endpoint at (1,2) and the other endpoint at (4,b). Find all possible values of b, separated by commas.
Using the equare of the distance formula
(4 -1)^2 + ( b - 2)^2 = 5^2
9 + (b -2)^2 = 25
(b -2)^2 = 25 - 9
(b - 2)^2 = 16 take both roots
b - 2 = 4 or b - 2 = -4
b = 6 b = -2
+42 
