Question

Find the possible values of a if the points with the given coordinates are the indicated distance apart.

1. (1, a), (3, -2); d=5​

Answer 1

Possible values of a = 2.58 and -6.58.

Explanation:

Using the distance formula

√(3- 1)^2 + (-2-a)^2) = 5

(3- 1)^2 + (-2-a)^2 = 25

4 + 4a + a^2 + 4 = 25

a^2 + 4a - 17 = 0

a = [-4 +/- √(4^2 - 4*1*-17) ] / 2

a = -2 +/- √84 / 2

a = 2.58, -6.58.