jmc

Question

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.

Accepted Answer

We use the distance formula: (4-1)^2 + (b-2)^2 = 5. Solving, we get 3^2 + (b-2)^2 = 5^2. (b-2)^2 = 16, so b-2=4 or b-2=-4. Solving, we get that b is one of 6, -2.