so, i'm trying to determine if the vectors(adsbygoogle = window.adsbygoogle || []).push({});

2,1,-1

1,1,0

2,-1,3

are coplanar. i take the triple product, finding the determinant of the matrix. it seems to be non-zero, but the answer key insists these are coplanar. am i wrong, or perhaps the book? any input would be appreciated!

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Vector algebra

**Physics Forums | Science Articles, Homework Help, Discussion**