posted by chirag on .
x is a number such that x2+3x+9=0. What is the value of x3?
since (x-3)(x^2+3x+9) = x^3 - 3^3
x^3 - 3^3 = 0
x^3 = 27
What a great way to do this question.
Did you see the round-about way I used ??
I was even thinking of using DeMoivre's theorem.
I was going to show an alternative direct solution, but when I saw where it was headed, I blew it off.
Can't believe you
(a) slogged through it all
(b) got it right!