1. **State the problem:** Determine if the matrix $$\begin{pmatrix}-1 & 0.5 \\ 4 & -2 \\ 4 & 1\end{pmatrix}$$ has full rank.
2. **Recall the definition:** The rank of a matrix is the maximum number of linearly independent rows or columns. For a matrix with dimensions $$3 \times 2$$, the maximum rank is $$2$$ (the smaller dimension).
3. **Check linear independence of columns:** The columns are $$\begin{pmatrix}-1 \\ 4 \\ 4\end{pmatrix}$$ and $$\begin{pmatrix}0.5 \\ -2 \\ 1\end{pmatrix}$$.
4. **Test if one column is a scalar multiple of the other:** Suppose $$\begin{pmatrix}0.5 \\ -2 \\ 1\end{pmatrix} = k \begin{pmatrix}-1 \\ 4 \\ 4\end{pmatrix}$$ for some scalar $$k$$.
5. Equate components:
$$0.5 = -1 \times k \Rightarrow k = -0.5$$
$$-2 = 4 \times k = 4 \times (-0.5) = -2$$ (matches)
$$1 = 4 \times k = 4 \times (-0.5) = -2$$ (does not match)
6. Since the third component does not satisfy the scalar multiple condition, the columns are linearly independent.
7. **Conclusion:** The matrix has rank $$2$$, which is full rank for a $$3 \times 2$$ matrix.
**Final answer:** The matrix has full rank (rank = 2).
Matrix Full Rank 9140C5
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