1. The problem statement, all variables and given/known data Three charges are fixed to an x, y coordinate system. A charge of +18 µC is on the y axis at y = +3.0 m. A charge of -16 µC is at the origin. Lastly, a charge of +45 µC is on the x axis at x = +3.0 m. Determine the magnitude and direction of the net electrostatic force on the charge at x = +3.0 m. Specify the direction relative to the -x axis. 2. Relevant equations F = k*q1*q2 / r^2 3. The attempt at a solution 9e9 * 18e-6 * 16e-6 / 3^2 = .28768 N and 9e9 * 45e-6 * 16e-6 / 3^2 = .7192N (.29^2 + .72^2)^.5 = .7746N tan^-1 ( .29/.72) = 21.8 degrees...90 - 22 = 68 degrees below the x-axis Can anyone figure out where I am going wrong? I don't get what i am not seeing. Thank you!