If T:R3→R3T: \mathbb{R}^3 \to \mathbb{R}^3T:R3→R3 is a linear operator with det(T)=0\text{det}(T) = 0det(T)=0, which of the following is true?
TTT is an isomorphism.
The nullity of TTT is 0.
TTT is not injective (one-to-one).
The rank of TTT is 3.