D3.2. Calculate D in rectangular coordinates at point P(2, -3, 6) produced by: (a) a point charge QA = 55 mC at Q(-2, 3, -6); (b) a uniform line charge PLB 20 mc/m on the x axis; (c) a uniform surface charge density Psc = 120 μC/m² on the plane z = -5 m. = Ans. 6.38ax -9.57ay + 19.14a² µC/m²; −212a, +424a² µC/m²; 60az μC/m²