Question 526112
find a rational zero of the polynomial function and use it to find all the zeros of the function f(x)=x^3-6x^2+7x+2
***
Using the rational roots theorem:
...0..|...1......-6........7..........2..............
...1..|...1......-5........2..........4............
...2..|...1......-4.......-1.........0 (2 is a root)
(x-2)(x^2-4x-1)
solve (x^2-4x-1) by following quadratic equation:
{{{x = (-b +- sqrt( b^2-4*a*c ))/(2*a) }}}
answers are:
x=-0.236
or 
x=4.236
..
Rational roots are: -0.236, 2, and 4.236