3. Minimize the following boolean functions using the Karnaugh map method in standard SOP form and POS shirt form (a) \( f(x, y, z)=\sum(2,3,6,7) \) (b) \( f(x, y, z)=x y+x^{\prime} y^{\prime} z^{\prime}+x^{\prime} y z^{\prime} \) (c) \( f(w, x, y, z)=\Sigma(4,6,7,15) \) (d) \( f(w, x, y, z)=\Pi(0,1,2,6,8,9,12) \). e.with truth table: