Using the Operator $a=1 \angle 120^{\circ}$ , Evaluate the Following in Polar Form: (A)

Essay

Using the operator $a=1 \angle 120^{\circ}$ , evaluate the following in polar form: (a) $(a+1) /$ $\left(1+a-a^{2}\right)$ , (b) $\left(a^{2}+a+j\right) /\left(j a-a^{2}\right),\left(\right.$ c) $(1-a)\left(1+a^{2}\right)$ , (d) $\left(a+a^{2}\right)\left(a^{2}+1\right)$ .