Find the Roots (Zeros) f(x)=x^3+x^2+3x-9

$f (x) = x^{3} + x^{2} + 3 x - 9$

Set $x^{3} + x^{2} + 3 x - 9$ equal to $0$ .

$x^{3} + x^{2} + 3 x - 9 = 0$

Graph each side of the equation. The solution is the x-value of the point of intersection.

$x \approx 1.40818927$