Question

6.
If p, q are the zeroes of the polynomial
f(x) = x2 + k(x - 1) - C, then (p - 1)(q - 1)
is equal to
(A) c-1
(B) 1-C
(C) C
(D) 1 + c​

Answer 1

The correct option is: (B) 1- c

Explanation:

Given equation is x² + k(x- 1) - c

= x² + kx - (k + c)

Since, p and q are the zeroes,

… p + q = -k and pq = -(k+ c)

Now, (p - 1) (q - 1) = Pq - q - p + 1

= pq - (p + q)+ 1 = -(k+ c)-(-k) + 1

= -k - c + k + 1 = 1 - c