2021 · Q11
For which values of k, does the equation x² − kx + 2 = 0 have real and distinct solutions ?
Elementary MathematicsAlgebra
- A−2√2 < k < 2√2
- Bk < −2√2 only
- Ck > 2√2 only
- Dk < −2√2 or k > 2√2
Explanation
Real and distinct solutions require discriminant Δ = k² − 8 > 0. This inequality holds exactly when |k| > 2√2, i.e. k < −2√2 or k > 2√2. This is option (d).