\documentstyle{amsppt} \magnification 1200 \NoRunningHeads %%\hoffset=.5in 1.\ \ Let $v_1 = (1,2),\ \ v_2=(3,0),\ \ v_3=(1,1).$ \itemitem{a)}Is $\{v_1, v_2\}$ linearly independent? \vfill \itemitem{b)} Is $\{v_1, v_2, v_3\}$ linearly independent? \vfill \itemitem{c)} Let $u = (0,1)$. Express $u$ as a linear combination of $v_1, v_2$. \newpage 2.\ \ Let $\Bbb V$ be the vector space of all $2 \times 2$ matrices and $\Bbb W$ be the subset of $\Bbb V$ such that $$\Bbb W = \{A \in \Bbb V| A_{11} + A_{22} = 0\}.$$ \itemitem{a)}Show that $\Bbb W$ is a vector space. \vfill \itemitem{b)} What is the dimension of $\Bbb W$? \vfill \itemitem{c)}Find a basis for $\Bbb W$. \newpage 3.\ \ Let $\Cal P_2$ be the vector space of all polynomials of degrees less or equal to 2. Let $f_0(x) = 1,\ f_1(x) = x+1.\ \ f_2(x) = x^2+x+1$ \itemitem{a)} Prove that $\Cal B= \{f_0, f_1, f_2\}$ is a basis for $\Cal P_2$. \vfill \itemitem{b)}Let $f(x) = x^2-x$. What are the coordinates of $f$ in the ordered basis $\Cal B$? \newpage 4.\ \ Let $T : R^4 \longrightarrow R^4$ be a linear transformatin defined by $T \Bbb X = A \Bbb X$ where $$A = \left[ \matrix 1&0&2&1\\ 1&1&3&1\\ 0&1&1&0\\ 0&2&2&3 \endmatrix \right]$$ \itemitem{a)}Find the Null space of $T, N_T$. \vfill \itemitem{b)}Find a basis for $N_T$. \vfill \itemitem{c)}Find a basis for $R_T$, the range of $T$. \newpage 5.\ \ Let $T$ be a linear operator on $R^2$ such that $T(e_1) = (1,2), T(e_2) = (2,1)$. \itemitem{a)}Find $T(x,y)$ for any $(x,y) \in R^2$. \vfill \itemitem{b)}Is $T$ invertible? If it is, find $T^{-1}$. \end