Question bank/JEE Main/Mathematics

Let f(x) = sgn (x2 - 4 | x | + k). If f(x) is discontinuous at
exactly four points, then the range of k is

A(0, 1)B(0, 2)C(0, 3)D(0, 4)

Show answer and solution▾

x2 - 4| x | + k must have 4 real roots
[IMAGE] - k ∈ (-4, 0)
k ∈ (0, 4).

Source: Grass-G / M-01 Mathematics Paper-1.docx