6.1 Given an op amp with gain $a = 10^3 \frac{V}{V}$, find (a) $v_N$ if \$\newline v_P = 0$ and $v_O = 3$ V, (b) $v_N$ if $v_P = 1.0$ V and $v_O = -10$ V,\newline (c) $v_O$ if $v_N = 5.002$ V and $v_P = 4.998$ V, and (d) $v_P$ if \newline $v_N = 3.5$ V and $v_O = 3.5$ V.