The points (2,1), (4,0), and (-4,k^2) are collinear. What is the value of k?

Answer 1

So the slope between any segment must be the same

slope for first two points:
(0-1)/(4-2) = -1/2

slope between 1st and last point:
(k^2 - 1)/(-4-2) = (k^2 - 1)/-6

so (k^2 -1)/-4 = -1/2
2k^2 - 2 = 4
2k^2 = 6
k^2 = 3
k = ± √3