If the positive scale function y = (1 = k) x and the inverse scale function y = (1-k) / X have intersection points, the value range of K is obtained

If the positive scale function y = (1 = k) x and the inverse scale function y = (1-k) / X have intersection points, the value range of K is obtained

Method 1
According to the meaning of (1 + k) x = (1-k) / x, there are non-zero roots,
That is, (1 + k) x ^ 2 = 1-k has non-zero roots
That is, (1-k) / (1 + k) > 0
Get - 1