Linear independence


Given a set of vectors v1,vnv_{1},\ldots v_{n}, the vectors are said to be linearly independent if there does not exists a nontrivial Linear combination of them that is equal to zero. In other words, there does not exists a set of constants α1,,αnR\alpha_{1},\ldots,\alpha_{n}\in \mathbb{R}, not all zero, such that

α1v1++αnvn=i=1nαivi=0\alpha_{1} v_{1}+\ldots+\alpha_{n}v_{n}=\sum_{i=1}^{n} \alpha_{i}v_{i}=0

If such a set exists, the vectors are instead linearly dependent. If two vectors vv and ww are linearly dependent, one is always a multiple of the other, which means that there exists a constant cRc\in \mathbb{R} for which v=cwv=cw.