Question

If two of the zeros of the cubic polynomial ax³ + bx² + cx + d are 0 then the third zero is ______.

Options

• `(-b)/a`

• `b/a`

• `c/a`

• `(-d)/a`

Answer 1

If two of the zeros of the cubic polynomial ax³ + bx² + cx + d are 0 then the third zero is `underlinebb((-b)/a)`.

Explanation:

Let α, 0, 0 be the zeros of ax³ + bx² + cx + d.

Then, sum of zeros = `(-b)/a`

⇒ `α + 0 + 0 = (-b)/a`

⇒ `α = (-b)/a`

Hence, the third zero is `(-b)/a`.