Question

find the value of k if -1 is a zero of the polynomial P of X equal to K x square - 4 x + k​

Answer 1

p (x) = x2 - 4x + k

if -1 is the zero of the p (x) that means polynomial should be equal to 0

put x = -1 in p (x)

(-1)^2-4 (-1)+k = 0

1+4+k = 0

k = -5