The problem of solving quadratic inequality of one variable If the domain of kx2-6kx + (K + 8) under y = root is r, then the value range of K is r_____ [Note: 2 in kx2 is square, need to explain in detail]

The problem of solving quadratic inequality of one variable If the domain of kx2-6kx + (K + 8) under y = root is r, then the value range of K is r_____ [Note: 2 in kx2 is square, need to explain in detail]

The definition field is r, which means that any value of X can make the formula under the root sign hold, that is, the formula under the root sign is always greater than or equal to 0, as long as it is transformed into a formula independent of X