Cubic equation / cubic polynomial : x³ - 3 p x - 2 q = 0
Solution is given by:
Given y³ - 7 y + 6 = 0
So substituting p = 7/3 and q = -3 we get :
We can try to find the solutions of the polynomial equation: y³ - 7 y + 6 = 0 by
constant term / coefficient of y³: +or - 6 /1 or its factors : + or - of 6, 3, 2, 1
So we can try these 8 possibilities. It so happens that 1, 2, -3 are the roots.
By using the other formula :
This solution gives complex numbers. So it requires to convert them in the polar coordinate form
and then take cube root and then add the two cube roots.
Then we get the same answers.