Hi there,

I want to find the x intercept for the function y= x^{3}-9x^{2}+15x+30. The answer from the graphing calculator is x=-1.133. I am aware of the factor theorem and the rational factor theorem (for an integer other than 1 or 0 as a leading coefficient). But in this case neither of these can work. Is there any algebraic method to find this root or trial and error is the only way? Any help will be greatly appreciated.

Thanks

Nikunj