Question

• Show that (-1+ √3i)³ is a real No.

Answer 1

$( - 1 + \sqrt{3} i {}^{2}$

$- 1 + 3 \sqrt{3} i - 3( - 3) - 3 \sqrt{3} i$

$(a - b) {}^{3} = a ^{3} - b ^{3} - 3ab(a - b)$

$= - 1 + 9 = 8$

Hence , It is a real number.