Solution

This is an exercise in definition! It is so simple, that it looks impossible to do. Study it well.

Suppose [Maple Math] . We need to show that [Maple Math] are all zero.

If we take [Maple Math] , then the equation can be rewritten as [Maple Math] . By hypothesis that [Maple Math] are independent, so [Maple Math] are all zero, in particular [Maple Math] are all zero!