Let $n \in \mathbb{N}$
True or false? If the column-vectors of $A \in \mathbb{R}^{n \times n}$ are linearly dependent, then we have that $\text{det(A)}=0$
The statement should be true and it shouldn't even matter if the column- or row-vectors are linearly dependent. Linearly dependent means we will always get $\text{det(A)}=0$.
I hope this is right? If it's right, can you tell me a better reasoning?
It is right. If they are dependent, the rank isn't $n$, and a well-known theorem tells you that $det(A)=0$. That's the usual reasoning.