Work out coplanar vectors instantly with clear inputs, formula shown and shareable results.
Three vectors are coplanar exactly when the parallelepiped they span has zero volume, so the test is whether the scalar triple product a·(b × c) vanishes.
Coplanarity test
a · (b × c) = 0 ⇔ the three vectors are coplanar
Yes — the third is the sum of the first two, so the triple product is 0.
Yes. Two vectors from a common origin always determine a plane, unless one is zero.