Modulus equationMediumQuestion 220022
Question
The number of real solutions of |x² − 1| = x is:
- A0
- B1
- C2Correct
- D3
Correct answer
2
Explanation
Case 1: x²−1 = x (x ≥ 0 region where x²≥1): x²−x−1=0, x=(1+√5)/2 (valid). Case 2: 1−x² = x → x²+x−1=0, x=(−1+√5)/2 (positive, valid since x²<1 here). Total: 2 solutions.