If α, β, γ are the roots of cubic equation a x3 + cx = 0. Find the value of α3 + β3 + γ3.
Solution: For ax3 + cx = 0
= x(ax2 + c) = 0
x = 0 or ax2 + c = 0
From the above equation we conclude that one root of equation ax3 + cx should be zero
and Sum of the root = α + β + γ = 0
We know α3 + β3 + γ3 = 3αβγ
Since one root is zero
3αβγ = 0
So,α3 + β3 + γ3 = 0