2024 · Q38
If the roots of the equation x² - (k - 2)x + (k + 1) = 0 are equal, then what are the values of k?
Elementary MathematicsAlgebra
- A0, 4
- B0, 8
- C4, 4
- D2, 6
Explanation
Equal roots require the discriminant to vanish: Δ = (k−2)² − 4·1·(k+1). Expanding gives Δ = k²−4k+4−4k−4 = k²−8k = k(k−8). Setting Δ = 0 yields k = 0 or k = 8 — option B.