Let a,b and c be distinct positive numbers. If the vectors a^i+a^j+c^k, ^i+^k and c^i+c^j+b^k are co-planar, then c is equal to

Let a,b and c be distinct positive numbers. If the vectors a^i+a^j+c^k

1.	Let a,b and c be distinct positive numbers. If the vectors a^i+a^j+c^k, ^i+^k and c^i+c^j+b^k are co-planar, then c is equal to
Answer» Let $a, b$ and $c$ be distinct positive numbers. If the vectors $a^i + a^j + c^k,^i +^k$ and $c^i + c^j + b^k$ are co-planar, then $c$ is equal to