The two dimensions: three point particles are fixed in place in an xy plane. Particle A consists of mass mA = 4 g, particle B consists of mass 2.00mA, and particle C consists of mass 3.00mA. A fourth particle D, having mass 4.00mA, is to be positioned near the other three particles. What (i) x-coordinate and (ii) y-coordinate must particle D be positioned so that the total gravitational force on particle A from particles B, C, and D is zero (d = 18 cm)?