Question 12
PolynomialsFind the value of p and q such that (x − 1) and (x − 3) are factors of px3 + qx2 + 11x − 6.
- A.−1, −6
- B.1, −6
- C.1, 6
- D.6, −1
Show the answer and explanation
Answer: B (1, −6)
Explanation
Put x = 1: p + q + 5 = 0. Put x = 3: 27p + 9q + 27 = 0, i.e. 3p + q + 3 = 0. Subtracting gives 2p = 2, so p = 1 and q = −6.