Tagged Questions
1
vote
1answer
215 views
Meaning of this 4x4 determinant
Let $p,q,r$ and $s$ be four points on the plane. Moreover, $p,q,r$ are given in clockwise order. My book said that the following determinant is positive if and only if $s$ lies inside the circle ...
3
votes
2answers
144 views
How do I prove that the following method to find whether a point lies within a polygon is correct?
I came across the following method to determine whether a given point lies inside a convex polygon - however, I'm not sure how to prove it.
Given any three points on the plane $(x_0,y_0)$, ...