Question

Alpha beta gamma are the zeroes of the cubic polynomial kx3-5x+9 if alpha cube+beta cube +gama cube =27 find k

Answer 1

Using the relation between the zeros and co - efficients,
We get
Alpha * beta * gamma = - d/a
= - 9/k
Now
Alpha 3+beta3+gamma3 = 27
=3 alpha * beta * gamma =27
=3*-9/k =27
=-27/k=27
Therefore
K= -1