An induction machine has stator winding which produce an mmf of the form 100cos(100 4 ) s sm f = t + f where sm f is measured in the ccw direction (as normal). the mechanical rotor speed is 400 rad/s in the ccw direction. the rotor currents have the form 100sin( 2) cos( 2) ar br i at i b ct = + = + where rm f is measured ccw relative to the rotor (as normal) and a, c > 0 . find numerical values for a , b , and c.