If one of the zeroes of a quadratic polynomial of the form x2 + ax + b is the negative of the other, then it


let p(x) = x2 + ax + b

And let α be one of the zeroes


- α is the other zero of the polynomial p(x)


Product of the zeroes = constant term ÷ coefficient of x2


Product of the zeroes = b


α(- α) = b


- α2 = b


i.e. b is negative.


Sum of the zeroes = - (coefficient of x) ÷ coefficient of x2


α - α = - a


0 = - a


a = 0


The polynomials can be written as x2 - α2 (No linear term and negative constant term)

10
1