If one root of the equation x^2 + px + 12 = 0 is 4, while the equation x^2 + px + q = 0 has equal roots, then the value of 'q' is
- A. 49/4
- B. 4
- C. 3
- D. 12
Answer: A. 49/4
Explanation: Since 4 is a root of x² + px + 12 = 0: 4² + 4p + 12 = 0 ⇒ 4p = −28 ⇒ p = −7. For x² − 7x + q = 0 to have equal roots, discriminant D = (−7)² − 4(1)(q) = 0 ⇒ 49 − 4q = 0 ⇒ q = 49/4.