(c) $\left( 3 + \omega + 3\omega^{2} \right)^{4} = \left\lbrack 3 + \left( 1 + \omega^{2} \right) + \omega \right\rbrack^{4}$ $= \lbrack - 3\omega + \omega\rbrack^{4}$ $= ( - 2\omega)^{4}$ $= 16\omega$
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.