Homework Statement
Let E1 = (1, 0, ... ,0), E2 = (0, 1, 0, ... ,0), ... , En = (0, ... ,0, 1)
be the standard unit vectors of Rn. Let x1 ... ,xn be numbers. Show that if
x1E1+...+xnEn=0 then xi=0 for all i.
Homework Equations
The Attempt at a Solution
Proof By contradiction...