Let `veca , vecb and vecc` be three non-zero vectors such that `veca + vecb + vecc = vec0 and lambda vecb xx veca + vecbxxvecc + vecc xx veca = vec0` then find the value of `lambda`.

Explanation

To solve the problem step-by-step, we start with the given conditions:

1. **Given Conditions**:
\[ \vec{a} + \vec{b} + \vec{c} = \vec{0} \]
\[
\lambda (\vec{b} \times \vec{a}) + (\vec{b} \times \vec{c}) + (\vec{c} \times \vec{a}) = \vec{0}
...