If one of the zeroes of a cubic polynomial x³ + ax² + bx + c is 1, then the product of the other two zeroes is:

Correct option is C

One root is 1. Let the roots be: 1, β, γ
We are to find the product of the other two zeroes: β × γ

Formula used:

Sum of roots = –a

Sum of product of roots two at a time = b

Solution:
Sum of roots:
1 + β + γ = –a
=> β + γ = –a – 1 ...(1)

Sum of product of roots two at a time:
1×β + βγ + γ×1 = β + γ + βγ = b ...(2)

Substitute (1) into (2):
(–a – 1) + βγ = b
=> βγ = b + a + 1

Correct answer is (c)