Difficulty: Medium
Correct Answer: p = 1 and q = -2
Explanation:
Introduction / Context:
Here the symbolic coefficients p and q also equal the roots of their own quadratic. This creates equations among p and q via Vieta’s relations that must be satisfied simultaneously.
Given Data / Assumptions:
Concept / Approach:
For monic x^2 + px + q = 0 with roots r1 = p and r2 = q: sum r1 + r2 = −p and product r1*r2 = q (Vieta). This yields a system in p and q.
Step-by-Step Solution:
Verification / Alternative check:
With p = 1, q = −2, the quadratic x^2 + x − 2 = 0 has roots 1 and −2, matching p and q.
Why Other Options Are Wrong:
They violate either the sum or product condition; check Vieta’s relations to see inconsistencies.
Common Pitfalls:
Missing the special solution q = 0, p = 0 (not listed) or confusing coefficient p with root p without applying Vieta correctly.
Final Answer:
p = 1 and q = −2
Discussion & Comments