1 Answer | Add Yours
`f(x) = x^2+2x+9`
`x^2+2x+9 = lambda`
`x^2+2x+9-lambda = 0`
If the above quadratic function does not have real roots then the discriminant(Delta) should be less than 0.
`Delta = 4-4xx1xx(9-lambda)<0`
So for `f(x) = lambda` where there is no solutions `lambda<8`
We’ve answered 333,797 questions. We can answer yours, too.Ask a question