Question

For what value of p are the points(2,1),(p,-1),(-1,3) collinear?

Answer 1

Since, the points are collinear...

$\mathbb{Therefore, their slopes will be equal...}$

=> (-1-1)/(p-2) = (3+1)/(-1-p)

=> -2/(p-2) = 4/(-1-p)

=> 2+2p = 4p-8

=> 2p = 10

=> p = 5....

hope it helps...

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