find the values of x for which the curve has horizontal tangents

N 7
we have
[tex]y=x^3-2x^2+x+1[/tex]step 1
Find out the first derivative
[tex]y^{\prime}=3x^2-4x+1[/tex]step 2
Equate the first derivative to zero
[tex]3x^2-4x+1=0[/tex]Solve the quadratic function
the solutions are