2019 · Q26
For any two real numbers a and b, √((a - b)²) + √((b - a)²) is
Elementary MathematicsAlgebra
- Aalways zero
- Bnever zero
- Cpositive only if a ≠ b
- Dpositive if and only if a > b
Explanation
√((a−b)^2) = |a−b| and √((b−a)^2) = |b−a| = |a−b|. Their sum is 2|a−b|, which is positive exactly when a ≠ b.