Question

[2(cos 210°+ i sin 210°)][4(cos 120°+i sin 120°)]​

Answer 1

Answer:

[2 (cos 210° + i sin 210°)] [4 ( cos 120°+ i sin 120°)] . :

Answer 2

{2( cos (180 + 30) + sin (180 + 30)}{4(cos(90+30)+sin (90 + 30)}

2( -√3/2 + -1/2 ) {4(-√3/2 + 1/2)}

= (-√3 -1 )( 2-2√3)

= -2√3 + 6 - 2 + 2√3

= 4