1. The problem statement, all variables and given/known data The electric fields from three coherent sources are described by E1 = E0 sin omega t, E2 = E0 sin(omega t + phi), and E3 = E0 sin(omega t + 2phi). Let the resultant field be represented by EP = ER sin(omega t + alpha). Use phasors to find ER and alpha when (a) phi = 20.0 degree, (b) phi = 60.0 degree, and (c) phi = 120 degree. (d) Repeat when phi = (3pi/2) rad. Derive the general algebraic solution as well. 2. Relevant equations sin(a+b)=sinacosb+cosasinb E1+E2=ER 3. The attempt at a solution Moreover, I am not sure how to calculate α and what is meant by deriving the general algebraic solution?