If the function y = the independent variable of [KX's Square - 6kx + K + 8] under the root sign, take all real numbers and find the value range of constant K

If the function y = the independent variable of [KX's Square - 6kx + K + 8] under the root sign, take all real numbers and find the value range of constant K

K is greater than or equal to 0 and less than or equal to 1
2. When k is not equal to 0, it is a quadratic function. Because under the root sign, the range of value is always greater than or equal to 0 in the domain of definition, so K is greater than 0, and the minimum value is x = 3 at the axis of symmetry, then the formula under the root sign is greater than or equal to zero