Let f (x) = x ^ 2-2x + 1-k ^ 2, for any x ∈ (0, positive infinity) f (x) > 2k-2, the value range of K is obtained

Let f (x) = x ^ 2-2x + 1-k ^ 2, for any x ∈ (0, positive infinity) f (x) > 2k-2, the value range of K is obtained

If f (x) > 2k-2 is constant, that is, if f (x) - 2K + 2 > 0 is constant, then x & # 178; - 2x + 1-k & # 178; - 2K + 2 > 0 is constant, then x ∈ (0, + infinity). First, find the symmetry axis of quadratic function - 2A B = 1, and the function image opening upward, we can get the minimum value when x = 1, if x ∈ (0, + infinity) x & # 178; - 2x + 1-k & # 178; - 2K