If `veca, vecb and vecc` are three non-coplanar non-zero vectors, then prove that `(veca.veca) vecb xx vecc + (veca.vecb) vecc xx veca + (veca.vecc)veca xx vecb = [vecb vecc veca] veca`

Explanation

As `veca ,vecb and vecc` are non- coplanar, `vecb xx veca,veccxxveca and vecaxxvecb` are also non-coplanar, So, any vector con be expressend as a linear combination of these vectors.
`veca=lambdavecbxxvecc+mu vecc xx veca+ v vecaxxvecb`
`veca.veca=lambda[vecbveccveca],veca.vecb=mu [vecc vecavecb], veca.vecc=v[vecavecbvecc]`
`veca=((veca.veca)vecbxxvecc)/([vecb veccveca])+((veca.vecb)veccxxveca)/([veccvecavecb])+((veca.vecc)vecaxxvecb)/([vecavecbvecc])`