# Basis in C-vector space

1. Jan 26, 2009

### jeffreylze

1. The problem statement, all variables and given/known data

determine whether or not the given set is a basis for C^3 ( as a C-vector space)

(a) {(i,0,-1),(1,1,1),(0,-i,i)}
(b) {(i,1,0),(0,0,1)}

2. Relevant equations

3. The attempt at a solution

All I did was to put the 3 vectors in part (a) into a matrix as 3 columns. Then I determined that the matrix has 3 leading entries, hence it is a basis. But when I tried using the same method for part (b), it doesnt work. Why is that so?

2. Jan 26, 2009

### Staff: Mentor

The set in b has only two vectors, which isn't enough for a basis for C^3. There are some vectors in C^3 that aren't any linear combination (i.e., a sum of (complex) scalar multiples of (i, 1, 0) and (0, 0, 1).

3. Jan 26, 2009

### jeffreylze

But what i did for part(a) is right?

4. Jan 26, 2009

### Staff: Mentor

Assuming your work is correct, yes. A basis for C^3 has to have three vectors in it. If you have three vectors that are linearly independent, that's a basis.