Question

If 2 is a zero of polynomial p(x) =x3-4x2+kx-2 find the value of k

Answer 1

2 is the zero of the polynomials p(x)=x³-4x²+kx-2


x+2=0
x. =-2


Put the value in the eq.

p(x)= x³-4x²-kx-2
= (-2)³-4(-2)²-k(-2)-2
= -8-4×4+2k-2
= -8-16-2+2k
= -26+2k

Transfer -26 to the L.H.S

26=2k

K=26/2=13