Question

if -1 is a zero of the polynomial p(X) = x^3 +6x^2 +11x --k. find k

Answer 1

if -1 is a zero of the polynomial p(X) = x^3 +6x^2 +11x-k then

p (x)=0

Now the substituting the value of x in the given polynomial.

p (-1)=(-1)^3+6(-1)^2+11 (-1)-k

p (-1)=-1+6-11-k

p (-1)=-6-k

Now

-6-k=0

-6=k

k=-6