Question

If two zeroes of the polynomial x³ + x² − 9x − 9 are 3 and −3, then its third zero is

Options

• -1

• 1

• -9

• 9

Answer 1

Let `alpha = 3` and `beta = -3` be the given zeros and  y  be the third zero of the polynomial `x^3 + x^2 -9x-9` then

Bt using `alpha + beta + y = (-text{coefficient of }x^2)/(text{coefficient of } x^3)`

`alpha + beta + y = -1/1`

`alpha + beta + y = -1`

Substituting `alpha = 3` and `beta =-3` in `alpha + beta + y = -1`, we get

` 3 - 3 + y =-1`

`y = -1`

Hence, the correct choice is `(a).`