Consider two point charges 91 = 5nC and 92 = 7nC positioned at x1 = (2 - 3 + 4k)cm and (61+8-2k)cm, respectively. X2 = (a) Find the electric field at position x = (5 1+2 } +9k)cm and express it in the form E (Ex + Ey + Ez )N/C with explicit numerical values of the three components. (b) Find two positions x' at which the electrostatic field generated by the two charges is E' (-5000 + 3000 + 1000 k)N/C = =