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Fp3 vectors

Why does the cross product of PQ and PR give u the normal vector? Im confused..


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Original post by GPODT
Why does the cross product of PQ and PR give u the normal vector? Im confused..


Posted from TSR Mobile


Because PQ and PR both lie in the plane. The only vectors perpendicular to both of them are ones that are perpendicular to the plane.
Hence the cross product gives you a normal vector for the plane.
Reply 2
Avatar for the bear
the bear
20
the cross product always generates a vector perpendicular to the crossed vectors. As ghostwalker said since the crossed vectors both lie in the plane the resulting vector must be in the normal direction.
Reply 3
Avatar for yaboy
yaboy
Original post by the bear
the cross product always generates a vector perpendicular to the crossed vectors. As ghostwalker said since the crossed vectors both lie in the plane the resulting vector must be in the normal direction.


nope
Reply 4
Avatar for the bear
the bear
20
Original post by yaboy
nope


care to expand ?
Reply 5
Avatar for GPODT
GPODT
OP
16
Original post by ghostwalker
Because PQ and PR both lie in the plane. The only vectors perpendicular to both of them are ones that are perpendicular to the plane.
Hence the cross product gives you a normal vector for the plane.


Original post by the bear
the cross product always generates a vector perpendicular to the crossed vectors. As ghostwalker said since the crossed vectors both lie in the plane the resulting vector must be in the normal direction.

Cheers!

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