X³ - 53 x - 42 = 0
solutions can be obtained using standard formulae
x = -6.84579 Cubic equation / cubic polynomial : x³ - 3 p
x - 2 q = 0
Solution is given by:
By substituting p = 53/3 and q = 21 we get:
This formula yields in complex numbers. A little difficult to solve. we have to represent complex numbers in polar form and then take cube roots and add the two cube roots.
P = 53/3 and q = 21: so
These are the three roots of the given polynomial.